Task 4.2 Cell life cycle Look at the picture and answer the questions:
What periods of interphase are indicated by numbers 1 - 3?
What is the set of chromosomes and DNA in different periods of interphase?
What periods of mitosis are indicated by numbers 4 - 7?
What is the set of chromosomes and DNA in different periods of mitosis?
Fill the table:
| periods of interphase and mitosis | ongoing processes | Number of chromosomes (n) and the amount of DNA (s) |
| Presynthetic (G 1) Synthetic (S) Postsynthetic (G 2) | ||
| metaphase Telophase |
Test 1 During what period of the mitotic cycle does the amount of DNA double?
During the presynthetic period.
in the synthetic period.
in the post-synthetic period.
In metaphase.
Test 2 During what period does cell growth take place?
During the presynthetic period.
in the synthetic period.
in the post-synthetic period.
In metaphase.
Test 3 At what period of the life cycle does a cell have a set of chromosomes and DNA 2n4c and is preparing for division?
During the presynthetic period.
in the synthetic period.
in the post-synthetic period.
In metaphase.
Test 4 During what period of the mitotic cycle does the spiralization of chromosomes begin, the nuclear envelope dissolves?
During the presynthetic period.
in the synthetic period.
in the post-synthetic period.
In metaphase.
Test 5 During what period of the mitotic cycle do chromosomes line up along the equator of the cell?
During the presynthetic period.
in the synthetic period.
in the post-synthetic period.
In metaphase.
Test 6 During what period of the mitotic cycle do chromatids move away from each other and become independent chromosomes?
During the presynthetic period.
in the synthetic period.
in the post-synthetic period.
In metaphase.
Test 7 In what periods of mitosis is the number of chromosomes and DNA equal to 2n4c?
In prophase.
In metaphase.
In anaphase.
In telophase.
Test 8 At what period of mitosis is the number of chromosomes and DNA equal to 4n4c?
In prophase.
In metaphase.
In anaphase.
In telophase.
Test 9 What is the inactive part of DNA in a cell called?
Chromatin.
Euchromatin.
Heterochromatin.
All DNA in a cell is active.
Test 10 What are chromosomes called during interphase?
Chromatin.
Euchromatin.
Heterochromatin.
Chromosomes.
Give answers to the questions:
What is a diploid set of chromosomes?
What is a haploid set of chromosomes?
What is the set of chromosomes and DNA in the presynthetic period of interphase?
What is the set of chromosomes and DNA in the postsynthetic period of interphase?
What is the set of chromosomes and DNA in the prophase and metaphase of mitosis?
What is the set of chromosomes and DNA in the anaphase of mitosis?
What is the set of chromosomes and DNA in the telophase of mitosis?
How many DNA molecules are in the nucleus of a human somatic cell before mitosis?
How many DNA molecules are in the nucleus of a human somatic cell after mitosis?
What are the chromosomes called during interphase?
1. Interphase. 2. Chromatin. 3. Chromosome. 4. Chromatids. 5. Centromere. 6. Prophase. 7. Metaphase. 8. Anaphase. 9. Telophase. 10. Diploid set of chromosomes.
Subject: Cell division. Meiosis Task 4.7. First and second divisions of meiosis
Look at the picture and answer the questions:
What is the set of chromosomes and DNA in cells before the first division of meiosis?
What is the set of chromosomes and DNA in cells at different periods of the first division of meiosis?
What is the set of chromosomes and DNA in cells before the second division of meiosis?
What is the set of chromosomes and DNA in cells at different periods of the second division of meiosis?
At what stage of meiosis do conjugation and crossing of chromosomes take place?
In meiosis, the genetic material is recombined three times. When?
What is the biological meaning of meiosis?
Fill the table:
| divisions of meiosis | ongoing processes | Number of chromosomes (n) and the amount of DNA (s) |
| Prophase-1 Metaphase-1 Anaphase-1 Telophase-1 | ||
| Interphase | ||
| Prophase-2 Metaphase-2 Anaphase-2 Telophase-2 |
Specify the correct answers:
Test 1 When does conjugation of homologous chromosomes occur during meiosis?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
Test 2 What is the set of chromosomes and DNA at the end of the 1st division of meiosis?
Test 3 What is the set of chromosomes and DNA at the end of the 2nd division of meiosis?
Test 4 In what stages of meiosis is the set of chromosomes and DNA 1n4c?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
Test 5 In what stages of meiosis is the set of chromosomes and DNA 2n4c?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
Test 6 In what stages of meiosis is the set of chromosomes and DNA 1n2c?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
Test 7 In what stages of meiosis is the set of chromosomes and DNA 2n2c?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
Test 8 In what stages of meiosis is the set of chromosomes and DNA 1n1c?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
***Test 9. During what stages of meiosis does recombination of genetic material take place?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
Test 10 During what stages of meiosis does crossing over occur?
Prophase 1. 5. Prophase 2.
Metaphase 1. 6. Metaphase 2.
Anaphase 1. 7. Anaphase 2.
Telophase 1. 8. Telophase 2.
Give answers to the questions:
What is the set of chromosomes and DNA before the first division of meiosis?
What is the set of chromosomes and DNA before the second division of meiosis?
What chromosomes are called homologous?
What processes occur in prophase 1 of meiosis?
In what phases of the first division of meiosis does the recombination of genetic material occur?
What is the set of chromosomes and DNA in prophase-2 and metaphase-2?
In what phase of the second meiotic division does the recombination of genetic material take place?
What is the set of chromosomes and DNA at the end of the second meiotic division?
How many cells are formed as a result of meiosis from one parent cell?
1. Homologous chromosomes. 2. Conjugation. 3. Crossing over. 4. Diploid set of chromosomes. 5. Haploid set of chromosomes. 6. Reduction division of meiosis. 7. Recombination to anaphase-1. 8. Recombination to anaphase-2. 9. The biological meaning of meiosis.
Topic: Asexual and sexual reproduction Task 4.12. Various forms of asexual reproduction
Look at the picture and answer the questions:
What forms of asexual reproduction are indicated in the figure by numbers 1 - 6?
What genetic material do the offspring have during asexual reproduction?
Fill the table:
Task 4.14. Comparison of asexual and sexual reproductionFill the table:
| Comparable Features | asexual reproduction | |
| The number of individuals involved in reproduction offspring genetic material Recombination of genetic material Selection value |
Task 4.15. Asexual and sexual reproduction
Specify the correct answers:
Test 1 What form of asexual reproduction is most typical for mosses and ferns?
Test 2 What form of asexual reproduction is most typical for hydra, yeast?
binary division. 5. Cloning.
Schizogony. 6. Vegetative propagation.
Fragmentation. 7. Polyembryony.
Budding. 8. Sporulation.
Test 3 What form of asexual reproduction is used to propagate fruit and berry crops?
binary division. 5. Cloning.
Schizogony. 6. Vegetative propagation.
Fragmentation. 7. Polyembryony.
Budding. 8. Sporulation.
Test 4 What natural form of asexual reproduction is known in humans?
binary division. 5. Cloning.
Schizogony. 6. Vegetative propagation.
Fragmentation. 7. Polyembryony.
Budding. 8. Sporulation.
Test 5 What form of asexual reproduction is typical for planaria, some annelids?
binary division. 5. Cloning.
Schizogony. 6. Vegetative propagation.
Fragmentation. 7. Polyembryony.
Budding. 8. Sporulation.
Test 6
Offspring have the genes of only one, the mother's organism.
The offspring are genetically different from the parent organisms.
One individual participates in the formation of offspring.
Two individuals usually participate in the formation of offspring.
Test 7 What form of reproduction allows you to adapt to changing environmental conditions?
Asexual reproduction.
Sexual reproduction.
Both asexual and sexual reproduction equally.
The form of reproduction does not matter.
**Test 8. Specify the correct statements:
Parthenogenesis is a special form of asexual reproduction.
Parthenogenesis is a special form of sexual reproduction.
Parthenogenetic development is known in aphids, bees, and daphnia.
Parthenogenetic development is known in humans.
**Test 9. Specify the correct statements:
Hermaphrodites are organisms that can form both male and female gametes.
The gametes have a haploid set of chromosomes, the zygote is diploid.
B.L. Astaurov developed methods for the targeted production of 100% of individuals of the same sex.
Bacteria divide by mitosis.
**Test 10. Specify the correct statements:
Asexual reproduction has no advantages over sexual reproduction.
Gametes and zygote have a haploid set of chromosomes.
Two individuals always take part in sexual reproduction.
Sexual reproduction dramatically increases hereditary variability descendants.
Topic: Formation of germ cells and fertilization Task 4.16. Gametogenesis
Look at the picture and answer the questions:
What is indicated in the figure by the numbers 1 - 6?
What is the set of chromosomes in the breeding zone, where the precursors of gametes divide mitotically?
What is the set of chromosomes in the growth zone before the first division of meiosis?
What is the set of chromosomes and DNA after the first division of meiosis? After the second division?
How many normal eggs are formed from one oocyte entering meiosis?
Task 4.17. The structure of germ cells
Look at the picture and answer the questions:
*** What is indicated in the figure by numbers 1 - 12?
What is the size of a human egg?
What is in the cytoplasm of the egg?
Where are the nucleus and mitochondria located in the spermatozoon?
Task 4.18. Gametogenesis. Fertilization
Specify the correct answers:
Test 1 What set of chromosomes do the precursors of gametes have in the breeding zone?
diploid.
Haploid.
Spermatogonia are diploid, ovogonia are haploid.
Spermatogonia are haploid, ovogonia are diploid.
Test 2 What set of chromosomes do cells have in the maturation zone after the first division of meiosis?
Test 3 What set of chromosomes do gametes have?
Test 4 How many normal eggs are produced from one oocyte after two divisions of meiosis?
Test 5 How many normal spermatozoa are formed from one spermatocyte after two divisions of meiosis?
Test 6 Where is the Golgi complex located in the spermatozoon?
In the head.
In the intermediate section.
In the ponytail.
Test 7 Where are the mitochondria located in the sperm?
In the head.
In the intermediate section.
In the ponytail.
Test 8 Where are the centrioles located in the spermatozoon?
In the head.
In the intermediate section.
In the ponytail.
**Test 9. Specify the correct statements:
In the growth zone, the chromosome set is 2n.
In the maturation zone, two divisions of meiosis occur - reduction and equational.
Oogenesis produces four normal eggs from one oocyte.
During oogenesis, one normal egg and four directional (polar) bodies are formed from one oocyte.
***Test 10. Specify the correct statements:
The human egg is about 0.1 mm in size.
Human eggs are formed at the embryonic stage.
The human egg has two shells - shiny and radiant.
The human egg lacks ribosomes and mitochondria.
Look at the picture and answer the questions:
*** What is indicated in the figure by the numbers 1 - 21?
Where are the microspores of flowering plants formed?
*** What is formed from integuments? From the walls of the ovary?
Specify the correct answers:
Test 1 How many ovules can be in a pistil?
Always alone.
Usually equal to the number of seeds.
Usually equal to the number of fruits.
Equal to the number of pestles.
Test 2 A flower is an organ of asexual and sexual reproduction. What is asexual reproduction?
in the formation of seeds.
in fruit formation.
In the formation of dispute.
in the formation of gametes.
Test 3 What parts of a flower form a perianth?
A calyx of sepals.
A corolla of petals.
Cup and whisk.
Calyx, corolla, androecium and gynoecium.
Test 4 What is the male gametophyte of flowering plants?
A collection of stamens.
Pollen bag.
Microspore.
Pollen grain.
Test 5 What is the female gametophyte of flowering plants?
Pestle.
The ovary of the pestle.
Ovule.
Embryonic sac.
Test 6 What is produced from a fertilized egg?
The germ of the seed.
Endosperm.
Test 7 What is formed from the fertilized central cell?
The germ of the seed.
Endosperm.
Test 8 What is formed from integuments?
Pericarp.
Testa.
Endosperm.
Cotyledons.
Test 9 What is the pericarp formed from?
From integuments.
From the walls of the ovary.
From pestle.
From the flower bed.
Test 10 Who discovered double fertilization
S.G. Navashin.
I.V. Michurin.
N.I.Vavilov.
G. Mendel.
Give answers to the questions:
What is the set of chromosomes in the somatic cells of a flowering plant?
What is the male gametophyte of flowering plants?
How many cells are in a mature male gametophyte, what are they called?
What is the female gametophyte of flowering plants?
How many cells are in a mature female gametophyte, what are they called?
What is produced from a fertilized egg?
What is formed from the fertilized central cell?
What is formed from integuments (covers of the ovule)?
What is formed from the walls of the ovary?
What is formed from the ovule?
What is formed from the ovary of the pistil?
Who discovered double fertilization in flowering plants?
1. Sporophyte of flowering plants. 2. Flower. ***3. Androecium. ***4. Gynoecium. ***five. The male gametophyte of flowering plants. ***6. The female gametophyte of flowering plants. 7. Double fertilization of flowering plants. 8. Endosperm. 9. Seed germ. 10. Sperm. ***eleven. Integuments. 12. Micropyle. ***13. Nucellus. 14. Ovule.
Topic: Individual development of organisms Task 4.23. The main stages of embryogenesis
Look at the picture and answer the questions:
*** What is indicated in the figure by the numbers 1 - 10?
*** What is further formed from the blastocoel?
What is the name of the hole in the gastrula?
What germ layer does the neural tube develop from?
What is the name of an embryo with a formed axial complex?
What happens if we take a portion of the ectoderm from which the nervous system is formed from one gastrula and transplant it under the abdominal ectoderm of another gastrula?
Fill the table:
| germ layers | Derivatives of the germ layers |
| ectoderm | |
| Endoderm | |
| mesoderm |
Specify the correct answers:
Test 1.What is formed as a result of complete crushing of the zygote?
Blastula.
Gastrula.
Test 2. What is the name of the cavity inside the blastula?
Blastocoel.
Gastrocel.
Secondary body cavity.
Test 3. What is the name of a two-layer embryo with germ layers: ectoderm and endoderm?
Gastrula.
Blastula.
Test 4. What is the name of the cavity into which the primary mouth leads?
Blastocoel.
Gastrocel.
Secondary body cavity.
Mixed body cavity (myxocoel).
Test 5. What organisms are classified as deuterostomes?
Coelenterates and sponges.
Flat and round worms.
Mollusks and arthropods.
Echinoderms and chordates.
Test 6. What is the name of an embryo with an axial complex of organs?
Gastrula.
Blastula.
Test 7. Specify derivatives of ectoderm:
Test 8. Specify derivatives of endoderm:
Skin epidermis. 6. Digestive system.
Epithelium of the digestive system. 7. Digestive glands.
Circulatory system. 8. Respiratory system.
excretory system. 9. Reproductive system.
Nervous system. 10. Sense organs.
Test 9. Specify derivatives of mesoderm:
Skin epidermis. 6. Digestive system.
Epithelium of the digestive system. 7. Digestive glands.
Circulatory system. 8. Respiratory system.
excretory system. 9. Reproductive system.
Nervous system. 10. Sense organs.
Test 10 Specify animals with indirect postembryonic development:
Mammals. 5. Butterflies.
Birds. 6. Locust.
Reptiles. 7. Spiders.
Amphibians. 8. Cockroaches.
Biological dictation:
What is the name of the individual development of an organism from the formation of a zygote to the end of life?
What is the development of an organism from zygote to birth or to release from the egg membranes called?
What is the period from birth to the end of life called?
What is the end of the crushing period?
What is the name of an embryo with three germ layers: ectoderm, endoderm and mesoderm?
What organisms are classified as deuterostomes?
What is the name of the embryo in which the axial complex of organs has formed?
What organ systems are formed from the ectoderm?
Specify derivatives of endoderm.
Write down two types of animals with direct and indirect type of postembryonic development.
1. Fertilization. 2. Zygote. 3. Blastomeres. 4. Blastula. 5. Blastocoel (primary cavity). 6. Gastrula. 7. Mesoderm. 8. Secondary mouth. 9. Neirula. 10. Indirect postembryonic development.
Task 4.28. Questions to set off:
What is the name of the set of chromosomes characteristic of a species?
What is the set of chromosomes in somatic and germ cells?
How many chromosomes and DNA are there in different periods of interphase?
What are paired, identical chromosomes of a somatic cell called?
What is the name of the primary constriction and the ends of the chromosome?
How many chromosomes and DNA are there in a cell before mitosis and at the end of mitosis?
How many chromosomes and DNA are in prophase, metaphase and anaphase of mitosis?
What is the meaning of meiosis?
What are the first and second divisions of meiosis called?
What processes occur in the cell during prophase 1 of meiosis?
How many chromosomes and DNA before meiosis, after the first and second division?
What is the set of chromosomes and DNA in metaphase 1 and anaphase 1 of meiosis?
What is characteristic of interphase between the first and second divisions of meiosis?
What is the set of chromosomes and DNA in metaphase 2 and anaphase 2 of meiosis?
When does recombination of genetic material take place in meiosis?
List the phases of meiosis during which the chromosomes are bichromatid.
What is characteristic of asexual reproduction?
What is the name of the division in which multiple division of the nucleus occurs and several individuals are formed (in trypanosomes, malarial plasmodium)?
What is characteristic of the genotypes of daughter individuals in comparison with the maternal one during asexual reproduction?
What set of chromosomes do spores have?
What are the membranes of a mammalian egg called?
When does oogenesis begin in humans?
What is the name of reproduction, in which the development of a new organism comes from an unfertilized egg?
What is the set of chromosomes in gametogonia? Gametocytes of the 1st order? 2-order gametocytes?
What is formed after spermatogenesis from one spermatocyte?
What is formed after oogenesis from 1 oocyte?
Which organisms have external fertilization?
What are the male and female gametophytes of flowering plants?
What is formed from the integuments and the central cell of the embryo sac?
What is the pericarp formed from?
Who discovered double fertilization?
What are the stages of animal ontogeny?
What are the stages of animal embryogenesis?
What is formed as a result of zygote cleavage?
What is the name of the two-layer embryo of the lancelet?
What is formed from the ectoderm, endoderm and mesoderm of the neurula?
What germ layers form the spine, epidermis and lungs?
What animals are classified as deuterostomes?
Write three animals with direct postembryonic development.
Write three animals with indirect postembryonic development.
Task 4.1.
1 - equal-arm (metacentric) chromosomes; 2 - uneven shoulders (submetacentric); 3 - sharply uneven shoulders (acrocentric); 4 - telocentric chromosomes, in which the primary constriction is in the telomere region; 5 - primary constriction, centromere; 6 - secondary constriction (nucleolar organizer); 7 - satellite; 8 - chromatids; 9 - telomeres.
Two chromatids, two DNA molecules.
during mitosis and meiosis.
2n - 46, n - 23.
Paired, identical chromosomes carrying the same genes.
***About 8 cm in the first chromosome.
***About 2 meters.
Task 4.2.
1 - presynthetic (G 1), 2 - postsynthetic (S), 3 - postsynthetic (G 2).
G 1 - 2n2c; at the end of the S-period - 2n4c; G2-2n4c.
4 - prophase, 5 - metaphase, 6 - anaphase, 7 - telophase.
Prophase - 2n4c, metaphase - 2n4c, anaphase - 4n4c, telophase - 2n2c.
Task 4.3.
| periods of interphase and mitosis | ongoing processes | Number of chromosomes (n) and the amount of DNA (s) |
| Presynthetic (G 1) Synthetic (S) Postsynthetic (G 2) | Active cell growth, synthesis of structural and functional proteins. In mammalian cells, it lasts about 6-10 hours. DNA replication occurs. By the end of the period, each chromosome consists of two chromatids, two DNA molecules. Mitochondria, plastids, centrioles double. Proteins and energy for division are accumulated. | |
| metaphase Telophase | DNA spiralization occurs, the chromosomes shorten and thicken, the nucleoli disappear, the centrioles diverge and the fission spindle is formed. The nuclear envelope breaks into fragments. The chromatids are pulled apart to opposite poles, becoming independent chromosomes. Chromosomes despiralize, the nuclear envelope is formed, the nucleolus appears, and the spindle microtubules disappear. There is a division of the cytoplasm, in animal cells by constriction, in plant cells a barrier is formed. |
Task 4.4.
Test 1: 2. Test 2: 1. Test 3: 3. Test 4: 1. Test 5: 4. Test 6: 1. **Test 7: 1, 2.Test 8: 3. ***Test 9: 3. **Test 10: 3, 4, 5.
Task 4.5.
1. A double set of chromosomes is characteristic of somatic cells. 2. A single set of chromosomes, characteristic of germ cells. 3. 2n2c. 4. 2n4c. 5. 2n4c. 6.4n4c. 7. 2n2c. 8. 92 molecules. 9. 46. 10. Chromatin.
Task 4.6.
1. The period of time during which the cell is preparing for division. 2. Chromosomes in the interphase period. 3. Organelles of the cell nucleus, which are carriers of genes. 4. Structural elements of the chromosome, formed in the interphase as a result of DNA doubling. They are best seen during metaphase. 5. Part of the chromosome to which the microtubules of the division spindle are attached. 6. The initial period of mitosis, during which the chromosomes spiralize, the nuclear membrane dissolves, the nucleolus disappears, the centrioles diverge and the fission spindle forms. 7. The period of mitosis, during which the chromosomes line up in the plane of the equator of the cell, microtubules of the spindle are attached to the centromeres. 8. The period of mitosis, in which the chromatids diverge to the poles of the cell and become independent chromosomes. 9. During this period, the chromosomes decondense, nuclear membranes are formed and nucleoli appear, cytokinesis occurs - the division of the cytoplasm. 10. Double set of chromosomes.
Task 4.7.
1. 2n4c. 2. Prophase 1 - 2n4c, metaphase 1 - 2n4c, anaphase 1 - 2n4c, telophase 1 - n2c. 3.n2c. 4. Prophase 2 - n2c, metaphase 2 - n2c, anaphase 2 - 2n2c, telophase 2 - nc. 5. Into prophase 1. 6. Into prophase 1, into anaphase 1, into anaphase 2. 7. Reduction of the chromosome set to maintain a constant number of chromosomes during generational change and recombination of genetic material.
Task 4.8.
| divisions of meiosis | ongoing processes | Number of chromosomes (n) and the amount of DNA (s) |
| Prophase-1 Metaphase-1 Anaphase-1 Telophase-1 | In addition to the usual processes characteristic of prophase, there is conjugation of homologous chromosomes and crossing over - an exchange of sections of homologous chromosomes. Homologous chromosomes remain connected in some areas and are located in the plane of the equator of the cell. Spindle microtubules are attached to the centromeres. Homologous chromosomes, consisting of two chromatids, are pulled apart to opposite poles, each pole has a haploid set of chromosomes. Secondary recombination of genetic material occurs. Chromosomes despiralize, a nuclear envelope is formed, and the cytoplasm divides. | |
| Interphase | Short, no S-period. | |
| Prophase-2 Metaphase-2 Anaphase-2 Telophase-2 | Chromosomes shorten and thicken, centrioles diverge and the spindle is formed. The nuclear envelope is destroyed. Chromosomes are located in the plane of the equator of the cell. Spindle microtubules are attached to the centromeres. The chromatids are pulled apart to opposite poles, becoming independent chromosomes. Third recombination of genetic material. Chromosomes despiralize, the nuclear envelope is formed, the nucleolus appears, and the spindle microtubules disappear. The division of the cytoplasm takes place. |
Task 4.9.
Test 1: 1. Test 2: 2. Test 3: 1. **Test 4: 1, 2, 3,. Test 5: 8. **Test 6: 4, 5, 6. Test 7: 7.Test 8: 8. Test 9: 1, 3, 7. Test 10: 1.
Task 4.10.
1. 2n4c. 2.n2c. 3. Paired, identical chromosomes carrying the same genes. 4. Conjugation and crossing over. 5. In prophase and anaphase. 6. There is no S-period. 7.n2c. 8. Anaphase 2. 9. nc. 10. Four.
Task 4.11.
1. Paired chromosomes, identical in size, shape, composition and order of genes. 2. The process of close approach of homologous chromosomes. 3. Exchange of sections of homologous chromosomes. 4. Double set of chromosomes. 5. Single set of chromosomes. 6. The first division of meiosis, which results in a reduction in the number of chromosomes. 7. Occurs as a result of the divergence of homologous chromosomes to different poles of the cell. At each pole, a random combination of paternal and maternal chromosomes is assembled. 8. As a result of crossing over, the chromatids in the chromosome began to differ from each other; as a result of anaphase, chromosomes unique in terms of the set of genes are assembled at each pole. 9. Reduction of the chromosome set to maintain the constancy of the number of chromosomes during the change of generations and recombination of genetic material during the formation of gametes or spores.
Task 4.12.
1 - binary division; 2 - schizogony, multiple division; 3 - budding; 4 - fragmentation; 5 - vegetative reproduction; 6 - reproduction by spores.
Usually identical to the genetic material of the parent.
They won't, each spore formed as a result of meiosis has a unique set of genes.
Task 4.13.
| Forms of asexual reproduction | |
| asexual reproduction of bacteria Binary division schizogony sporulation budding Fragmentation Vegetative reproduction Polyembryony Cloning | Bisection, not mitosis, under favorable conditions occurs after 20 minutes. mitotic division. Characteristic of protozoa and somatic cells of multicellular organisms. Multiple division. Typical for protozoa and some algae. Spores can be formed mitotically (for example, in mosses) and meiotically (for example, in ferns). In the second case, the disputes are genetically unequal. It is characteristic of some fungi (for example, yeast), animals (for example, for freshwater hydra), some plants. Reproduction, in which the body is divided into fragments, each of which regenerates the missing organs. Propagation of plants by vegetative organs (root, leaves, shoots). Development of several embryos from one zygote. The ability to grow a genetically identical individual by transplanting a nucleus from a somatic cell into an egg from which the nucleus has previously been removed. |
Task 4.14.
| Comparable Features | asexual reproduction | sexual reproduction |
| 1. The number of individuals involved in reproduction 2. Genetic material of offspring 3. Recombination of genetic material 4. Importance for selection | Offspring have the genes of only one, the mother's organism. The genetic material is usually the same as that of the parent. Usually absent. Occurs if, for example, spores are formed as a result of meiosis. Leads to a rapid increase in the number of genetically identical offspring. | Differs from the genetic material of the parent organisms. Occurs during the formation of gametes and their random combination. Provides genetically heterogeneous material for natural selection. |
Task 4.15.
Test 1: 8. Test 2: 4. Test 3: 6. Test 4: 7. Test 5: 3. **Test 6: 1, 3. Test 7: 2.**Test 8: 2, 3. **Test 9: 1, 2, 3. Test 10: 4.
Task 4.16.
***1 - ovogonia; 2 - oocytes of the 1st order; 3 - oocytes of the 2nd order; 4 - the first guide body; 5 - egg; 6 - guide bodies of the 2nd order.
After the first division n2с, after the second - nс..
Task 4.17.
1 - chromosomes at the stage of metaphase 2. 2 - zona pellucida. 3 - radiant shell. 4 - the first guide body. 5 - the head of the spermatozoon. 6 - acrosome. 7 - core. 8 - centrioles. 9 - neck. 10 - mitochondria. 11 - intermediate department. 12 - flagellum.
About 0.1mm.
Even before birth, at the stage of the embryo.
The nucleus in the head, mitochondria in the intermediate section of the spermatozoon.
Task 4.18.
Test 1: 1. Test 2: 3. Test 3: 4. **Test 4: 1, 2, 4, 5. Test 5: 4. Test 6: 1. Test 7: 3.Test 8: 2. **Test 9: 1, 2, 4. **Test 10: 1, 2, 3.
Task 4.19.
***1 - peduncle; 2 - receptacle; 3 - sepals; 4 - corolla petals; 5 - filament; 6 - pollen bag; 7 - ovary of the pistil; 8 - ovules; 9 - integuments; 10 - micropyle; 11 - placenta; 12 - seed stalk; 13 - nucellus; 14 - egg; 15 - synergides; 16 - central cell; 17 - antipodes; 18 - chalaza; 19 - microsporangia; 20 - exine; 21 - intina; 22 - vegetative cell; 23 - generative cell; 24 - two sperm.
In microsporangia, in anther nests.
Pollen grain.
Embryonic sac.
The germ of the seed.
triploid endosperm.
From the integuments - the peel of the seed, from the walls of the ovary - the pericarp.
Task 4.20.
Test 1: 2. Test 2: 3. Test 3: 3. Test 4: 4. Test 5: 4. Test 6: 3. Test 7: 4.Test 8: 2. Test 9: 2. Test 10: 1.
Task 4.21.
1. Diploid. 2. Pollen grain. 3. Vegetative cell and two sperm. 4. Embryo sac. 5. Seven cells: an egg and two cells - synergids, a central cell and three cells - antipodes. 6. Seed germ. 7. Endosperm. 8. Seed rind. 9. Pericarp. 10. Seed. 11. Fruit. 12. S.G. Navashin.
Task 4.22.
1. Self flowering plant. 2. A modified shoot adapted for sexual reproduction. 3. The totality of stamens in a flower. 4. The set of pistils in a flower. 5. Pollen grain. 6. Embryo sac. 7. Fusion of one sperm with the egg, the second with the central cell. 8. Nutrient tissue of the seed. 9. Covers of the ovule. 10. The structure from which the seed subsequently develops.
Task 4.23.
***1 - blastocoel; 2 - blastoderm; 3 - blastopore, primary mouth; 4 - ectoderm; 5 - endoderm; 6 - gastrocoel; 7 - mesoderm; 8 - neural tube; 9 - chord; 10 - transplantation of a section of ectoderm from the dorsal side of one gastrula to the ventral side of the other; 11 - formation of an additional axial complex.
Blastula.
*** Primary body cavity.
Blastopore, primary mouth.
From the ectoderm.
An additional embryo will form.
Task 4.24.
| germ layers | Derivatives of the germ layers |
| ectoderm | The epidermis of the skin, hair, nails, sweat, sebaceous and mammary glands. From the neural plate - the nervous system, components of the organs of vision, hearing, smell, tooth enamel, epithelium of the oral cavity and rectum. |
| Endoderm | Intestines, liver, pancreas and lungs. |
| mesoderm | Cartilage and bone skeleton, connective tissue layer of the skin, skeletal muscles, excretory, circulatory and reproductive systems. |
Task 4.25.
Test 1: 2. Test 2: 1. Test 3: 1. Test 4: 2. Test 5: 4. Test 6: 3. **Test 7: 1, 2, 5.**Test 8: 6, 7, 8, 10. **Test 9: 3, 4, 8, 9. **Test 10: 4, 5, 6, 8.
Task 4.26.
1. Ontogeny. 2. Embryonic development. 3. Postembryonic development. 4. Blastula formation. 5. Gastrula. 6. Echinoderms and chordates. 7. Neirula. 8. The epidermis of the skin, hair, nails, sweat, sebaceous and mammary glands. From the neural plate - the nervous system, components of the organs of vision, hearing, smell, tooth enamel, epithelium of the oral cavity and rectum. 9. Intestines, liver, pancreas and lungs. 10. With direct - birds and spiders, with indirect - frogs and butterflies.
Task 4.27.
1. Fusion of germ cells. 2. Fertilized egg. 3. Cells resulting from the first divisions of the zygote. 4. An embryo with a primary cavity inside. 5. Cavity inside the blastula, primary cavity. 6. An embryo in which germ layers are formed: ectoderm, endoderm and mesoderm. 7. Third germ layer. 8. A hole formed when the cells of its wall are pushed into the cavity of the blastula. It later becomes the anus. 9. An embryo in which an axial complex of organs has formed. 10. Development with the larval stage.
Task 4.28.
1. Karyotype. 2. In somatic cells of organisms with a diploid set of chromosomes, the chromosome set is diploid, in gametes it is haploid; in somatic cells of an organism with a haploid set of chromosomes, the chromosome set is haploid, gametes are formed mitotically and have a haploid set of chromosomes. 3. G 1 - 2n2c, at the end of the S-period - 2n4c, G 2 - 2n4c. 4. Homologous. 5. The primary constriction is the centromere, the ends of the chromosome are telomeres. 6. Before mitosis 2n4c, after mitosis 2n2c. 7. In prophase - 2n4c, in metaphase - 2n4c, in anaphase - 4n4c. 8. Recombination of genetic material and reduction of the chromosome set in germ cells. 9. Reduction and equational. 10. DNA replication ends, conjugation, crossing-over occurs and the same processes occur as in the prophase of mitosis. 11. Before meiosis - 2n4c, after the first division - n2c, after the second - nc. 12. In metaphase 1 and anaphase 1 - 2n4c. 13. Short, no S-period. 14. In metaphase 2 - n2c, in anaphase 2 - 2n2c. 15. Into prophase 1, into anaphase 1, into anaphase 2. 16. Prophase 1, metaphase 1, anaphase 1, telophase 1, interphase 2, prophase 2, metaphase 2. 17. Daughter organisms have the genes of only one, the mother organism. 18. Shizogony. 19. If spores are formed as a result of mitosis, then they have the same chromosome set as the cells of the mother organism; if their formation is preceded by meiosis, the chromosome set is reduced and the genetic material is recombined. 20. In flowering plants, spores are haploid. Some groups of organisms may have a diploid set of chromosomes. 21. Two layers of cells, called the brilliant and radiant membranes. 22. At the third month of embryogenesis. 23. Parthenogenesis. 24. Gametogonia - 2n, gametocytes of the 1st order 2n4c, gametocytes of the 2nd order n2c. 25. Four spermatozoa. 26. One egg and three polar (direction) bodies. 27. Most fish and amphibians. 28. Male gametophyte - pollen grain, female gametophyte - embryo sac. 29. From integuments - seed coat, from the central cell - triploid endosperm. 30. From the walls of the ovary. 31. S.G. Navashin. 32. Embryogenesis and postembryonic development. 33. Cleavage (blastulation), gastrulation and organogenesis. 34. Blastula. 35. Gastrula. 36. From the ectoderm: the epidermis of the skin and its derivatives, the nervous system, the sense organs and the posterior pituitary gland. From the endoderm: the digestive and respiratory systems, the anterior pituitary gland and the thyroid gland. From the mesoderm: skeleton, muscles, reproductive, excretory and circulatory systems. 37. The spine - from the mesoderm, the epidermis of the skin - from the ectoderm, the lungs - from the endoderm. 38. Echinoderms and chordates. 39. Reptiles, birds, mammals. 40. Amphibians, insects, bony fish.
GBOU VPO FTA TTD Korolev MO
Training and metodology complex
in biology
Topic: "Reproduction and individual development of organisms"
for the specialty262019 "Design, modeling and technology of garments"
Developer: A. V. Tsareva - teacher of the discipline "Biology"
Korolev, 2014
Technological map of the complex
Goals: Educational: to form students' knowledge about the most important property of living organisms - reproduction, about its forms - asexual and sexual,about the types of cell division, the significance of cell division for unicellular and multicellular organisms, the morphology of chromosomes, the life and mitotic cycles, and the processes occurring in different periods of the mitotic cycle. To form knowledge about the features of spermatogenesis, oogenesis, the structure of germ cells and fertilization in animals, and double fertilization in angiosperms; to study the stages of individual development of organisms, the main stages of embryogenesis, derivative germ layers, types of postembryonic development. Show the harmful effects of nicotine, alcohol and other mutagens on the embryo.
Educational : improve students' skills to generalize, draw conclusions, analyze, compare, establish a causal relationship between environmental factors and consequences for hereditary material.
Educational : creating conditions for realizing the need for a competent attitude to one's health and environment, the formation of students' knowledge about the harmful effects of alcohol, nicotine, drugs on the development of the fetus and a negative attitude towards these phenomena;
instill in students the elements of a healthy lifestyle, rejection bad habits; formation of an active life position among students.
Intersubject communications.
Valeology Topic: "Health Risk Factors"
Methods: verbal, visual, problem-search, knowledge control.
Ensuring the lesson.
Visual aids:table "Scheme of mitosis", Scheme of meiosis", Gametogenesis".
Handout:didactic cards, test tasks.
Equipment : textbook, computer, multimedia presentations, videos.
Literature basic:
2. Galperin M.V. Environmental fundamentals nature management: textbook. - M.: Publishing House "FORUM", 2011. -256 p.
3. "General biology" 10-11 Belyaev D.K. - M.: Enlightenment, 2009. -304 p.
4. "General biology" Konstantinov VM., Rezanov A.G., Fadeeva E.O. Textbook for free software. - M.: publishing center "Academy", 2012, 256 p.
5. "General biology with the basics of ecology and environmental protection" Tupikin E.I. Textbook for open source software. - M.: Publishing Center "Academy", 2011, 384 p.
Additional sources:
- Konstantinov V.M. Ecological bases of nature management: textbook. Handbook for students of institutions environments. prof. education. - M.: Publishing Center "Academy", 2011. -208 p.
- Nikolaikin N.I. Ecology: a textbook for universities. – M.: Bustard, 2009. – 622 p.
- Internet Educational Resources
The student must know:essence of concepts: amitosis, mitosis, meiosis, interphase, replication, haploid, diploid, fertilization, gametogenesis, ontogenesis, embryogenesis;forms and methods of asexual and sexual reproduction; structure and functions of germ cells; the biological significance of crossing over; fertilization in animals and plants; stages of the embryonic period of development; the influence of the environment on the embryonic and postembryonic development of the organism; biogenetic law.
The student must be able to:explain the mechanisms of different ways of division and the processes of gametogenesis, fertilization, embryogenesis;show the influence of bad habits on ontogeny.
As a result of mastering this educational topic, the student must master the general (basic) and professional competencies:
1. General (basic competencies):
Ability to search, analyze, transform, apply information to solve problems;
Successful possession and use of information technologies;
Ability to cooperate with other people, dialogue, ability to work in a group;
Willingness to constantly acquire new knowledge;
Ability to set goals, plan, treat health responsibly, fully use personal resources;
Demonstrate the depth of the acquired knowledge and apply them in professional activities;
2. Professional competencies:
Understand the essence and social significance of their profession, show a steady interest in it;
The ability to develop and analyze the main directions of organizing one's life position, lifestyle, to implement measures for the development of oneself and others;
Be ready to take on moral obligations in relation to nature, society and man.
Lead a healthy lifestyle and participate in sanitary and hygienic education of the population.
Distribution of classes by topic:
3.1. Forms and methods of asexual reproduction. Cell division. Mitosis.
3.2. Sexual reproduction. Meiosis. Crossing over.
3.3. Gametogenesis. Fertilization.
3.4. Individual development of the organism. Embryogenesis.
3.5. Postembryonic development.
3.6. Individual human development. reproductive health. The consequences of the influence of alcohol, nicotine, narcotic substances, environmental pollution on human development.
The body is one. Diversity of organisms. Reproduction is the most important property of living organisms. Sexual and asexual reproduction. Meiosis. The formation of germ cells and fertilization.
Individual development of the organism. Embryonic stage of ontogeny. Main stages of embryonic development. Organogenesis. Postembryonic development.
The similarity of the embryos of representatives different groups vertebrates as evidence of their evolutionary relationship. Causes of violations in the development of organisms. Individual human development. reproductive health. The consequences of the influence of alcohol, nicotine, narcotic substances, environmental pollution on human development.
Demonstrations
Cell division. Mitosis. asexual reproduction of organisms. The formation of germ cells. Meiosis. Fertilization in plants. Individual development of the organism. Types of postembryonic development of animals.
Laboratory and practical work
Identification and description of signs of similarity between human embryos and other vertebrates as evidence of their evolutionary relationship.
Auditorium form of work:
- compiling a summary;
- work with educational literature;
- drawing up diagrams and tables;
- work with didactic cards and tests.
Extracurricular form of work:
- work with lecture notes;
- writing tests;
- preparation of messages and presentations on the topics:
"The influence of bad habits on the development of the fetus"
"Natural and artificial parthenogenesis",
"Cloning",
"Hermaphroditism",
"The role of hormones in the life of organisms",
"Aging and Immortality".
Lesson number 1.
Forms and methods of asexual reproduction.
Cell division. Mitosis.
Lecture
Reproduction is the most important property of living organisms. Reproduction at the molecular level - DNA replication; reproduction at the level of organelles - division of mitochondria, chloroplasts; reproduction at the level of cells - cell division. Underpins the transmission hereditary information, reproduction, growth, development, regeneration.
Chromosomes are carriers of hereditary information. The chromosome set characteristic of the species is karyotype; chromosome set received from parents - genotype, chromosomal set of gametesgenome. diploidset of chromosomes - double, haploid set is single.
Chromosome morphology: chromatids, centromere, chromosome arms and telomeres, secondary constriction. Biochemical composition - 60% proteins, 40% - DNA.
Cell division methods: amitosis - direct division; mitosis - indirect division; meiosis - division characteristic of the phase of maturation of germ cells.
amitosis, or direct division -a method of dividing the nucleus of somatic cells in half by constriction without the formation of chromosomes. If the division of the cytoplasm does not occur during amitosis, then two- and multinuclear cells arise. This method of division is characteristic of some protozoa, specialized cells or pathologically altered cells. The distribution of nuclear material turns out to be random and uneven. The resulting daughter cells are hereditarily defective.
Mitotic and life cycles.The period of existence of a cell from the moment of its formation by division of the mother cell (including division itself) to its own division or death is called life (cell) cycle.
The duration of the life cycle of different cells of a multicellular organism is different. Yes, cells nervous tissue after the completion of the embryonic period, they cease to divide and function throughout the life of the organism, and then die. The cells of the embryo at the stage of crushing, having completed one division, immediately proceed to the next, bypassing all other phases.
Mitosis - indirect division of somatic cells, as a result of which doubling first occurs, and then a uniform distribution of hereditary material between daughter cells.
biological significance mitosis:as a result of mitosis, two cells are formed, each of which contains the same number of chromosomes as there were in the mother. Daughter cells are genetically identical to the parent. The number of cells in the body increases, which is one of the main mechanisms of growth. Many plant and animal species reproduce asexually by mitotic cell division alone, so mitosis is the basis of reproduction. Mitosis ensures the regeneration of lost parts and cell replacement, which occurs to one degree or another in all multicellular organisms.
Mitotic cycleconsists of interphase and mitosis. The duration of the mitotic cycle varies greatly in different organisms. It usually takes 1-3 hours for the cell to divide directly, that is, the main part of the cell's life is in the interphase.
Interphase called the interval between two cell divisions. The duration of interphase, as a rule, is up to 90% of the entire cell cycle. Interphase consists of three periods: presynthetic, or G1; synthetic, or S; postsynthetic, or G2.
The initial segment of the interphase -presynthetic period(2n2с, where n is the number of chromosomes, c is the amount of DNA), period of growth beginning immediately after mitosis.Synthetic periodthe duration is very different: from several minutes in bacteria to 6–12 hours in mammalian cells. During the synthetic period, the most important event of interphase occurs - the duplication of DNA molecules. Each chromosome becomes two-chromatid, and the number of chromosomes does not change (2n4c).
post-synthetic period.Provides preparation of the cell for division and is also characterized by intensive processes of protein synthesis that make up the chromosomes; enzymes and energy substances necessary to ensure the process of cell division are synthesized.
Mitosis. For the convenience of studying the events occurring during division, mitosis is divided into four stages: prophase, metaphase, anaphase, telophase.
Prophase (2n4s). As a result of spiralization, the chromosomes are compacted and shortened. In late prophase, it is clearly seen that each chromosome consists of two chromatids connected by a centromere. Chromosomes begin to move towards the cell equator. The spindle is formed, the nuclear membrane disappears, and the chromosomes are freely located in the cytoplasm. The nucleolus usually disappears a little earlier.
metaphase (2n4s). Chromosomes line up in the plane of the equator, forming the so-calledmetaphase plate.The centromeres of chromosomes lie strictly in the plane of the equator. The spindle threads are attached to the centromeres of the chromosomes, some threads pass from pole to pole of the cell without attaching to the chromosomes.
Anaphase (4n4c). It begins with the division of the centromeres of all chromosomes, as a result of which the chromatids turn into two completely separate, independent daughter chromosomes. Then the daughter chromosomes begin to diverge towards the poles of the cell.
Telophase (2n2s). Chromosomes are concentrated at the poles of the cell and despiralized. The spindle of division is destroyed. A shell of the nuclei of daughter cells is formed around the chromosomes, then the division of the cytoplasm of the cell (or cytokinesis) occurs.
When animal cells divide, a furrow appears on their surface in the equatorial plane, which, gradually deepening, divides the mother cell into two daughter cells. In plants, division occurs by the formation of the so-calledcell plateseparating the cytoplasm. It arises in the equatorial region of the spindle, and then grows in all directions, reaching the cell wall.
forms of asexual reproduction.
Asexual reproduction is widespread in nature. It is most common in unicellular organisms, but is also common in multicellular organisms. The following features are characteristic: only one individual takes part in reproduction; carried out without the participation of germ cells; mitosis is the basis of reproduction; offspring are identical and are exact genetic copies of the parent. The advantage is the rapid increase in numbers.
Independent work of students with the text of the textbook: write out in a notebook the definitions of the main methods of asexual reproduction.
1. Binary division -division, in which two equivalent daughter cells (amoeba) are formed.
2. Multiple division, or schizogony. The mother cell breaks up into a large number of more or less identical daughter cells (malarial plasmodium).
3. Sporulation. Reproduction through spores - specialized cells of fungi and plants. If the spores have a flagellum and are mobile, then they are called zoospores (chlamydomonas).
4. Budding. On the maternal individual, an outgrowth is formed - a kidney, from which a new individual (yeast, hydra) develops.
5. Fragmentation -division of an individual into two or more parts, each of which develops into a new individual. In plants (spirogyra) and in animals (annelids). Fragmentation is based on the property regeneration.
6. Vegetative propagation.characteristic of many groups of plants. During vegetative propagation, a new individual develops either from a part of the mother or from special structures (bulb, tuber, etc.) specially designed for vegetative propagation.
Vegetative organ | Method of vegetative propagation | Examples |
Root | root cuttings | Rosehip, raspberry, aspen, willow, dandelion |
Root offspring | Cherry, plum, thistle, thistle, lilac |
|
Aerial parts of shoots | The division of the bushes | Phlox, daisy, primrose, rhubarb |
stem cuttings | Grapes, currants, gooseberries |
|
layering | Gooseberries, grapes, bird cherry |
|
Underground parts of shoots | Rhizome | Asparagus, bamboo, iris, lily of the valley |
Tuber | Potato, weekday, Jerusalem artichoke |
|
Bulb | Onion, garlic, tulip, hyacinth |
|
Corm | Gladiolus, crocus | |
Sheet | leaf cuttings | Begonia, Gloxinia, Coleus |
7. Polyembryony. Reproduction during embryonic development, in which several embryos develop from one zygote - twins (identical twins in humans). Offspring are always of the same sex.
8. Cloning. Artificial method of asexual reproduction. Does not occur in natural conditions. Clone - genetically identical offspring obtained from one individual as a result of one or another method of asexual reproduction.
|
- Working with the text of the textbook and the diagram of mitosis, answer the questions:
2. What is the name of the chromosome set received from parents?
3. What is the name of the set of gamete chromosomes?
4. What are the structures at the ends of chromosomes called?
5. How many chromatids are in the chromosome before mitosis? After mitosis?
6. How many chromosomes and DNA in different periods of interphase?
7. How many chromosomes and DNA are in the prophase of mitosis?
8. How many chromosomes and DNA are in the metaphase of mitosis?
9. How many chromosomes and DNA are in the anaphase of mitosis?
10. How many chromosomes and DNA are there in the telophase of mitosis?
Testing: "Mitosis"
1. During what period of the mitotic cycle does the amount of DNA double?
1. In the presynthetic period.
2. In the synthetic period.
4. In metaphase.
2. During what period does cell growth take place?
1.
During the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
3. At what period of the life cycle does a cell have a set of chromosomes and 2n4c DNA and is preparing for division?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
4. During what period of mitosis does the spiralization of chromosomes begin, and the nuclear membrane dissolves?
1. In anaphase.
2. In prophase.
3. In telophase.
4. In metaphase.
5. During what period of mitosis do chromosomes line up along the equator of the cell?
1. In prophase.
2. In metaphase.
3.
In anaphase.
4. In telophase.
6. During what period of mitosis do chromatids move away from each other and become independent chromosomes?
1. In prophase.
2. In metaphase.
3. In anaphase.
4. In telophase.
* 7. In what periods of mitosis is the number of chromosomes and DNA equal to 2n4c?
1. In prophase.
2. In metaphase.
3. In anaphase.
4. In telophase.
8. In what period of mitosis is the number of chromosomes and DNA equal to 4n4c?
1. In prophase.
2. In metaphase.
3. In anaphase.
4. In telophase.
9. What is the inactive part of DNA in a cell called?
1. Chromatin.
2. Euchromatin.
3. Heterochromatin.
4. All DNA in the cell is active.
*10. At what periods of the cell cycle is the number of chromosomes and DNA in a cell equal to 2n4c?
1. In the presynthetic period.
2. At the end of the synthetic period.
3. In the post-synthetic period.
4. In prophase.
5. In metaphase.
6. In anaphase.
7. In telophase.
- There are several correct answers to the question.
Answers on the topic "Mitosis". Test 1. 2. Test 2. 1. Test 3. 3. Test 4. 2. Test 5. 2. Test 6. 3. *Test 7. 1, 2. Test 8. 3. Test 9. 3. *Test 10. 2, 3, 4, 5.
Lesson number 2.
Sexual reproduction. Meiosis. Crossing over.
Front poll:
- What is the role of reproduction in nature?
- What are the characteristics of asexual reproduction?
- What is the meaning of asexual reproduction?
- Why graft fruit trees?
- What is characteristic of vegetative propagation?
- What are the forms of vegetative propagation?
- What forms of reproduction exist in the organic world?
Learning task:What is the biological significance of sexual reproduction?
Lecture
Meiosis. First division of meiosis.Meiosis is the main stage in the formation of germ cells. During meiosis, there is not one, as in mitosis, but two successive cell divisions. The first meiotic division is preceded by interphase I - the phase of cell preparation for division, at which time the same processes occur as in the interphase of mitosis.
The first meiotic division is called reduction, since it is during this division that a decrease in the number of chromosomes occurs, two cells are formed with a haploida set of chromosomes, but the chromosomes remain bichromatid. Immediately after the first division of meiosis, the second takes place - like a normal mitosis. This division is called equational, since during this division, the chromosomes become single chromatid.
The biological significance of meiosis: due to meiosis, a reduction in the number of chromosomes occurs. Four haploid cells are formed from one diploid cell. Thanks to meiosis, genetically different gametes are formed, because. in the process of meiosis, the recombination of genetic material occurs three times: due to crossing over; random and independent divergence of homologous chromosomes, and then chromatids. Meiosis maintains the constancy of the diploid set of chromosomes in somatic cells.
The first and second divisions of meiosis consist of the same phases as mitosis, but the essence of the changes in the hereditary apparatus is different.
Prophase I. The longest and most complex phase of meiosis. Consists of a number of successive stages. Homologous chromosomes begin to be attracted to each other by similar regions and conjugate. conjugation called the process of close convergence of homologous chromosomes. A pair of conjugating chromosomes is called bivalent. Bivalents continue to shorten and thicken. The chromosome set can be designated as 2n4c. Each bivalent is formed by four chromatids. Therefore it is called tetrad. major event is an crossing over - exchange of parts of chromosomes. Crossing over leads to the first recombination of genes during meiosis. At the end of prophase I, the nuclear envelope and nucleolus disappear. Bivalents move to the equatorial plane. Centrioles, if present, move to the poles of the cell, and the spindle is formed.
Metaphase I (2n; 4s). The formation of the fission spindle is completed. Spiralization of chromosomes is maximum. Bivalents are located in the plane of the equator. Moreover, the centromeres of homologous chromosomes are facing different poles of the cell. The location of bivalents in the equatorial plane is equally probable and random, that is, each of the paternal and maternal chromosomes can be turned towards one or the other pole. This creates prerequisites for the second gene recombination during meiosis. The spindle fibers are attached to the centromeres of chromosomes.
Anaphase I (2n; 4s). Whole chromosomes diverge to the poles, not chromatids, as in mitosis. Each pole has half of the chromosome set. Moreover, pairs of chromosomes diverge as they were located in the plane of the equator during metaphase. As a result, a wide variety of combinations of paternal and maternal chromosomes arise, and a second recombination of genetic material occurs.
Telophase I (1n; 2c). In animals and some plants, the chromatids despiralize and a nuclear membrane forms around them. Then the cytoplasm divides (in animals) or a separating cell wall is formed (in plants). In many plants, a cell from anaphase I immediately transitions to prophase II.
Second division of meiosis. Interphase II (1n; 2c). It is characteristic only for animal cells. DNA replication does not occur.
The second stage of meiosis also includes prophase, metaphase, anaphase, and telophase. It proceeds in the same way as normal mitosis.
Prophase II (1n; 2c). Chromosomes spiralize, the nuclear membrane and nucleoli are destroyed, centrioles, if any, move to the poles of the cell, and a division spindle is formed.
Metaphase II (1n; 2c). The metaphase plate and spindle are formed, and the filaments of the spindle are attached to the centromeres.
Anaphase II (2n; 2c). The centromeres of the chromosomes divide, the chromatids become independent chromosomes, and the spindle fibers stretch them to the poles of the cell. The number of chromosomes in a cell becomes diploid, but a haploid set is formed at each pole. Since in metaphase II the chromatids of chromosomes are randomly located in the plane of the equator, the third recombination of the genetic material of the cell occurs in anaphase.
Telophase II (1n; 1s). The fission spindle threads disappear, the chromosomes despiralize, the nuclear envelope around them is restored, and the cytoplasm divides.
Thus, as a result of two successive divisions of meiosis, a diploid cell gives rise to four daughter, genetically different cells with a haploid set of chromosomes.
Drawing up a diagram of meiosis on the board:
Sexual reproduction.Sexual reproduction is carried out with the participation of two parent individuals (male and female), in which specialized cells are formed in special organs - gametes . The process of formation of gametes is called gametogenesis, the main stage of gametogenesis is meiosis. The daughter generation develops from zygotes - a cell formed as a result of the fusion of male and female gametes. The process of fusion of male and female gametes is calledfertilization. An obligatory consequence of sexual reproduction is the recombination of genetic material in the daughter generation.
Depending on the structural features of gametes, the following can be distinguishedforms of sexual reproduction: isogamy, heterogamy and ovogamy.
isogamy (1) - a form of sexual reproduction in which gametes (conditionally female and conditionally male) are mobile and have the same morphology and size.
Heterogamy (2) - a form of sexual reproduction in which female and male gametes are mobile, but female gametes are larger than male and less mobile.
Ovogamia (3) - a form of sexual reproduction in which the female gametes are immobile and larger than the male gametes. In this case, the female gametes are called eggs , male gametes, if they have flagella, -spermatozoa, if not, - sperm.
Ovogamy is characteristic of most animal and plant species. Isogamy and heterogamy are found in some primitive organisms (algae). In addition to the above, some algae and fungi have forms of reproduction in which germ cells are not formed: chologamy and conjugation. At chologamy unicellular haploid organisms merge with each other, which in this case act as gametes. The resulting diploid zygote then divides by meiosis to form four haploid organisms. At conjugations (4) the contents of individual haploid cells of the filamentous thalli are fused. Through specially formed channels, the contents of one cell flows into another, a diploid zygote is formed, which usually also divides by meiosis after a dormant period.
Sexual reproduction is characteristic of most living organisms. Advantages: each individual has a unique genotype, which allows, as a result of natural selection, to adapt to various environmental conditions.
The type of sexual reproduction is parthenogenesis - virgin development, when a new organism develops from an unfertilized egg (daphnia, aphids, drones, silkworms, rock lizards).
Tasks for consolidating and testing knowledge
- What is characteristic of sexual reproduction? (2 individuals, gametes..)
- What can animals be like during sexual reproduction? (dioecious, bisexual - hermaphrodites)
- What is parthenogenesis? (development from unfertilized egg)
- Under what conditions does parthenogenesis occur? (survival strategy)
- What is the survival strategy of fish? (laying a lot of eggs if you do not take care of the offspring)
- Pigeons and eagles lay 2 eggs each. Why are there a lot of pigeons, but eagles are rare? (a feature of the dwelling, and food)
- What are the gonads of vertebrates called? (testes, ovaries)
- What is sexual dimorphism? (difference between male and female)
Testing: "Meiosis"
Test 1 When does conjugation of homologous chromosomes occur during meiosis?
1. Prophase I.
2. Metaphase I.
3. Anaphase I.
4. Telophase I.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Telophase II.
Test 2 What is the set of chromosomes and DNA at the end of the 1st division of meiosis?
1. 1n1c.
2. 1n2c.
3. 1n4c.
4. 2n2c.
5. 2n4c.
6.4n4c.
Test 3 What is the set of chromosomes and DNA at the end of the 2nd division of meiosis?
1. 1n1c.
2. 1n2c.
3. 1n4c.
4. 2n2c.
5. 2n4c.
6.4n4c.
*Test 4. At what stages of meiosis is the set of chromosomes and DNA 2n4c?
1. Prophase I.
2. Metaphase I.
3. Anaphase I.
4. TelophaseI.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Telophase II.
Test 5 At what stage of meiosis is the set of chromosomes and DNA 2n2c?
1. Prophase I.
2. Metaphase I.
3. Anaphase I.
4. TelophaseI.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Telophase II.
*Test 6. At what stages of meiosis is the set of chromosomes and DNA 1n2c?
1. Prophase I.
2. Metaphase I.
3. Anaphase I.
4. TelophaseI.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Telophase II.
Test 7 At what stage of meiosis is the set of chromosomes and DNA 4n4c?
1. Prophase I.
2. Metaphase I.
3. Anaphase I.
4. TelophaseI.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Such a set of chromosomes and DNA cannot normally exist.
Test 8 At what stage of meiosis is the set of chromosomes and DNA 1n1c?
1. Prophase I.
2. Metaphase I.
3. Anaphase I.
4. TelophaseI.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Telophase II.
*Test 9. At what stages of meiosis does recombination of genetic material take place?
1. Prophase I.
2. Metaphase I.
3. Anaphase I.
4. TelophaseI.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Telophase II.
Test 10 At what stage of meiosis does crossing over occur?
- Prophase I.
2. Metaphase I.
3. Anaphase I.
4. TelophaseI.
5. Prophase II.
6. Metaphase II.
7. Anaphase II.
8. Telophase II.
Assignment on the topic "Meiosis". Test 1. 1. Test 2. 2. Test 3. 1. *Test 4. 1, 2, 3. Test 5. 7. *Test 6. 4, 5, 6. Test 7. 8, Test 8. 8. *Test 9.1, 3, 7. Test 10.1.
Homework:
Lesson number 3.
Gametogenesis. Fertilization.
Front poll:
Comparison of asexual and sexual reproduction according to the following characteristics:
- The number of individuals involved in reproduction;
Are gametes produced? Which method lacks meiosis?
- Who are the offspring like?
- What organisms are typical?
- Where is the fastest growing population?
Individual survey:
1. Characteristics of the 1st division of meiosis.
2. Characteristics of the 2nd division of meiosis.
3. Differences between meiosis and mitosis.
Work with cards at the board:
Write down the numbers of questions, against them - the correct answers.1. What is the asexual reproduction of an amoeba called? |
Learning new material.
1. Independent work of students with a textbook, filling in the table:
Comparable Features | female gametes | Male gametes |
1. Shape and dimensions | ||
2. Structural features | ||
3. Functions performed |
Gametes. These are germ cells, at the fusion of which a zygote is formed, giving rise to a new organism. They are highly specialized cells involved in the implementation of processes associated with sexual reproduction. Gametes have a number of features that distinguish them from somatic cells: the chromosome set of somatic cells is diploid (2n2c), and the gametes are haploid (nc); gametes do not divide; gametes, especially eggs, larger than somatic cells; the egg contains a lot of nutrients, the sperm contains little (practically absent); gametes have an altered nuclear-cytoplasmic ratio compared to somatic cells (in the egg, the nucleus occupies a much larger volume than the cytoplasm, in the sperm, on the contrary, and the nucleus has the same dimensions as in the egg). An active role in fertilization belongs to the spermatozoon. Therefore, it is small and mobile (in animals). The egg not only brings its own set of chromosomes to the zygote, but also ensures the development of the embryo in the early stages. Therefore, it is large in size and, as a rule, contains a large supply of nutrients.
Organization of animal eggs.The size of the eggs varies widely - from several tens of micrometers to several centimeters (a human egg is about 100 microns, an ostrich egg, which has a length of about 155 mm with a shell, is also an egg). The egg has a number of membranes located on top of the plasma membrane, and reserve nutrients. In mammals, the eggs have a shiny shell, on top of which there is a radiant crown - a layer of follicular cells.
The amount of nutrients accumulated in the egg cell depends on the conditions in which the embryo develops. So, if the development of the egg occurs outside the mother's body and leads to the formation of large animals, then the yolk can be more than 95% of the volume of the egg. A mammalian egg contains less than 5% yolk. In connection with the accumulation of nutrients, polarity appears in the eggs. Opposite poles are called vegetative and animal. Polarization is manifested in the fact that the location of the nucleus in the cell changes (it shifts towards the animal pole), as well as in the distribution of cytoplasmic inclusions (in many eggs, the amount of yolk increases from the animal to the vegetative pole).
organization of spermatozoa.The length of a human spermatozoon is 50–60 microns. The functions of the spermatozoon determine its structure. Head - the largest part of the spermatozoon, formed by the nucleus, which is surrounded by a thin layer of cytoplasm. At the anterior end of the head is acrosome - part of the cytoplasm with a modified Golgi apparatus. It produces an enzyme that helps dissolve the membranes of the egg. At the point of transition of the head to the middle part, an interception is formed - neck spermatozoon, which contains two centrioles. Behind the neck is middle part spermatozoa containing mitochondria, and tail, which has a structure typical of all eukaryotic flagella and is an organelle of sperm movement. The energy for movement is supplied by ATP hydrolysis, which occurs in the mitochondria of the middle part of the spermatozoon.
2. Explanation of the teacher using tables and compiling notes in a notebook.
Spermatogenesis, oogenesis. Gametogenesis - This is the process of development of sex cells - gametes. Gamete precursors ( gametocytes ) are diploid. The process of sperm formation is calledspermatogenesis,and the formation of eggs oogenesis (ovogenesis). In the sex glands, three different areas, or zones, are distinguished: the breeding zone, the growth zone, and the maturation zone. Spermatogenesis and oogenesis include three identical phases: reproduction, growth, maturation (division). In spermatogenesis, there is another phase - formation.
Reproductive phase: diploid cells divide repeatedly by mitosis. The number of cells in the gonads grows, they are called oogonia and spermatogonia. Set of chromosomes 2n. In the growth phase, their growth occurs, the resulting cells are calledoocytes of the 1st order And spermatocytes of the 1st order.In the maturation phase, meiosis occurs, as a result of the first meiotic division,gametocytes of the 2nd order(chromosome set n2c), which enter the second meiotic division, and cells with a haploid set of chromosomes (nc) are formed. Oogenesis practically ends at this stage, and spermatogenesis also includes a formation phase, during which spermatozoa are formed.
In contrast to the formation of spermatozoa, which occurs only after reaching puberty (in particular, in vertebrates), the process of formation of eggs begins even in the embryo. The reproduction period is fully carried out at the embryonic stage of development and ends by the time of birth (in mammals and humans). During the growth period, oocytes increase in size due to the accumulation of nutrients (proteins, fats, carbohydrates) and pigments - a yolk is formed. Then the oocytes of the 1st order enter the period of maturation. The first meiotic division produces two daughter cells. One of them, relatively small, calledfirst polar bodyis not functional, but another, larger one (oocyte 2nd order) undergoes further transformations.
The second division of meiosis is carried out up to the stage of metaphase II and will continue only after the second-order oocyte interacts with the spermatozoon and fertilization occurs. Thus, strictly speaking, not an ovum comes out of the ovary, but an oocyte of the 2nd order. After fertilization, it divides, resulting in ovum (or egg) and second polar body.However, traditionally, for convenience, an oocyte is called an oocyte of the 2nd order, ready to interact with a spermatozoon. Thus, as a result of oogenesis, one normal egg and three polar bodies are formed.
Fertilization. The set of processes leading to the fusion of male and female gametes, the unification of their nuclei and the formation of a zygote, which gives rise to a new organism, is called fertilization.
Distinguish external fertilization,in which the meeting of sperm and eggs occurs in the external environment, andinternal fertilization,in which the meeting of sperm and eggs occurs in the genital tract of the female.
Most often, the spermatozoon is completely drawn into the egg, sometimes the flagellum remains outside and is discarded. From the moment the sperm enters the egg, the gametes cease to exist, as they form a single cell - zygote. Depending on the number of spermatozoa that penetrate the egg during fertilization, there are: monospermia - fertilization in which only one sperm enters the egg (the most common fertilization), and polyspermy - fertilization, in which several sperm enter the egg. But even in this case, the nucleus of only one of the spermatozoa merges with the nucleus of the egg, and the remaining nuclei are destroyed.
Double fertilization.The most important advantages of flowering plants are the presence of a flower and a fruit. The flower promotes pollination, while the fruit protects the seeds and promotes their dispersal. The gametophyte of flowering plants is extremely reduced: the male is represented by a pollen grain, the female by the embryo sac.
In a flower, a pedicel, receptacle, perianth formed by a calyx of sepals and corolla petals, stamens and pistils are distinguished. Some flowers may have parts missing. Most flowers (over 70%) have both stamens and pistils. They are called bisexual (cherries, peas). Some flowers are same-sex: males contain only stamens, females only pistils. In monoecious plants, staminate and pistillate flowers are located on the same plant (watermelon, pumpkin, cucumber). In dioecious plants, male flowers are on one plant, female flowers on another (willow, poplar, hemp).
Once on the stigma of the pistil, pollen begins to germinate. The vegetative cell is responsible for the formation of the pollen tube, along which the generative cell moves, which gives rise to two sperm. The pollen tube moves along the style of the pistil and grows into the embryo sac through the micropyle. After penetrating the embryo sac, the tip of the pollen tube breaks and the sperm enters the embryo sac. One of the sperm fuses with the egg, forming a diploid zygote, and the second with the central nucleus of the embryo sac, forming a triploid nucleus, from which the endosperm, the nutritive tissue of the embryo, is formed. Synergids and antipodes degenerate. This process has been nameddouble fertilization.
Thus, after double fertilization, the seed embryo is formed from the egg, the endosperm from the central nucleus of the embryonic sac, the seed coat from the integuments, the seed from the entire ovule, and the pericarp from the walls of the ovary. In general, a fruit with seeds is formed from the ovary of the pistil. Double fertilization in flowering plants was discovered in 1898 by the Russian botanist Navashin in 1898.
Tasks for consolidating and testing knowledge
Frontal conversation.
1. When does spermatogenesis begin in humans?
2. When does human oogenesis begin?
3. What zones are distinguished in the gonads?
4. What is formed from the oocyte after meiosis?
5. What is the set of chromosomes in gametocytes of the 2nd order after the first division of maturation?
6. What is the set of chromosomes in gametes?
7. What are the names of the shells of the egg?
8. Where are mitochondria located in spermatozoa? Where are the centrioles located?
9. Which organisms have external fertilization?
10. What are the dimensions of the egg?
Dictation of terms "Reproduction of plants and animals"
1. Sex cells involved in reproduction are called ... ( Gametes. )
2. Male gametes are called ... ( spermatozoa. )
3. Female gametes are called ... ( Oocytes. )
4. The process of fusion of germ cells is called ... ( Fertilization. )
5. Animals in which some individuals produce only spermatozoa, while others produce eggs, are called ... ( Dioecious. )
6. Individuals capable of producing both male and female gametes in their body at the same time are called ..., or ... (Bisexual, or hermaphrodites.)
7. The ability of the embryo to develop from an unfertilized egg is called ... ( Parthenogenesis.)
8. A fertilized egg is called ... ( zygote.)
9. Sexual organs of males - ... ( Seeds.)
10. The genital organs of females - ... ( ovaries.)
11. Plants are characterized by two methods of reproduction - ... and ... (Asexual and sexual.)
12. The formation of new individuals from the root, shoot is called ... (vegetative reproduction.)
13. The organ of sexual reproduction of plants is ... ( Flower .)
14. The process by which pollen falls on the stigma of the pistil is called ... ( Pollination.)
15. Sperm develop into ... (pollen grains.)
16. The first sperm merges with ..., and the second sperm merges with ... ( Ovum; central cell.)
17. When a sperm cell fuses with an egg cell, ... ( zygote.)
18. When sperm merges with the central cell, ... ( Endosperm.)
19. The walls of the ovary become walls ... ( fruit.)
Lesson number 4.
Individual development of the organism. Embryogenesis.
Lecture
Embryogenesis. ontogeny, or individual development,the process of development of an individual from the moment of formation of a zygote to death. For convenience of study, it is divided into certain periods and stages:embryonic -from the formation of a zygote to birth or exit from the egg membranes andpostembryonic -from exit from the egg membranes or birth to the death of the organism.
The process of fertilization begins at the moment of contact between the sperm and the egg. From the moment the sperm enters the egg, the gametes cease to exist, as they form a single cell - zygote.
Cleavage, or blastulation, is a series of successive mitotic divisions of the zygote, as a result of which the cytoplasm of the egg is divided into numerous smaller cells containing nuclei. As a result of crushing, cells are formed, which are called blastomeres. Cleavage in representatives of different groups of animals has its own characteristics, but it ends with the formation of a structure similar in structure - blastula. The blastula is a single-layer embryo. It is made up of a layer of cells blastoderm, limiting cavity - blastocoel, or primary body cavity.Blastula is formed from the early stages of crushing due to the divergence of blastomeres. The resulting cavity is filled with liquid.
The next stage of embryogenesis is gastrulation (formation of germ layers). Gastrulation is characterized by intense movement of individual cells and cell masses. As a result of gastrulation, a two-layer, and then a three-layer embryo is formed (in most animals) - gastrula. Initially, the outer ( ectoderm) and internal (endoderm ) germ layers. Later, between the ecto- and endoderm, a third germ layer is laid - mesoderm. During the formation of the mesoderm, the formationsecondary body cavity, or coelom.
Next stage - organogenesis. Organogenesis can be divided into two phases: neurulation - the formation of a complex of axial organs (neural tube, chord, intestinal tube and mesoderm), the construction of other organs, the acquisition by various parts of the body of their typical form and features of internal organization.
An embryo at the stage of neurulation is called neurula. Formed on the dorsal sideneural plate,its edges thicken and rise, forming nerve folds. A U-shaped depression appears in the center of the plate -nervous groove,its edges touch and then close. As a result of these processes, a neural tube with a cavity arises - neurocele. From the ectoderm material, in addition to the neural tube, the epidermis and its derivatives (feathers, hair, nails, claws, skin glands, etc.), components of the organs of vision, hearing, smell, oral cavity epithelium, and tooth enamel develop.
Almost simultaneously with neurulation, the processes of laying the mesoderm and chord occur. Initially, folds are formed along the side walls of the primary intestine by protrusion of the endoderm. The area of endoderm located between these folds is separated from the bulk of the endoderm. This is how a chord appears. The resulting protrusions of the endoderm are laced from the primary intestine and turn into a series of segmentally located closed sacs calledcoelomic bags.Their walls are formed by the mesoderm, and the cavity inside is a secondary body cavity.
All types of connective tissue, dermis, skeleton, striated and smooth muscles, circulatory and lymphatic systems, and the reproductive system develop from the mesoderm.
From the material of the endoderm, the epithelium of the intestine and stomach, the digestive glands, the epithelium of the lungs and airways, the anterior and middle lobes of the pituitary gland, the thyroid and parathyroid glands develop.
Frontal conversation.
1. Development from the moment of fertilization to the birth of an organism is called ... ( germinal.)
2. The stage of division of the zygote into many cells is called ... ( Splitting up .)
3. A spherical embryo with a cavity inside is called ... ( Blastula.)
4. The stage of formation of three germ layers in the embryo is called ... ( Gastrula.)
5. The outer germ layer is called ... ( Ectoderm.)
6. The inner germ layer is called ... ( Endoderm.)
7. The middle germ layer is called ... ( Mesoderm.)
8. The stage at which the formation of organ systems occurs is called ... ( Neirula .)
9. The development of an organism from the moment of its birth to death is called ... (Postembryonic.)
Lesson number 5.
Postembryonic development.
Lecture
The postembryonic period of development begins at the moment of birth or release of the organism from the egg membranes and continues until its death. Postembryonic development includes: the growth of the organism; establishing the final proportions of the body; the transition of organ systems to the mode of an adult organism (in particular, puberty). Distinguishtwo main types of postembryonic development: 1) direct, 2) with transformation.
With direct development an individual emerges from the mother's body or egg membranes, which differs from the adult organism only in a smaller size (birds, mammals).
Distinguish: non-larval (oviparous) type, in which the embryo develops inside the egg (fish, birds); intrauterine type in which the embryo develops inside the mother's body and is associated with it through the placenta (placental mammals).
During development with transformation (metamorphosis), a larva emerges from the egg, arranged more simply than an adult animal (sometimes very different from it); as a rule, it has special larval organs, often leads a different way of life than an adult animal (insects, some arachnids, amphibians).
For example, in tailless amphibians, a tadpole larva emerges from the egg shells. It has a streamlined body shape, a tail fin, gill slits and gills, lateral line organs, a two-chambered heart, and one circulation. Over time, under the influence of thyroid hormone, the tadpole undergoes metamorphosis. His tail resolves, limbs appear, the lateral line disappears, lungs and the second circle of blood circulation develop, i.e. gradually it acquires features characteristic of amphibians.
Lesson number 6.
Individual human development. reproductive health. The consequences of the influence of alcohol, nicotine, narcotic substances, environmental pollution on human development.
Lecture
The development of the human body. Individual human development (ontogeny) begins from the moment of fertilization, when the female (ovum) and male (sperm) germ cells merge. Initial stages development takes place in the genital tract of a woman, therefore, it is customary to divide the entire ontogeny into prenatal and postnatal (from Latin natus - childbirth) periods, i.e. prenatal and postnatal.
In the prenatal (intrauterine) period of ontogenesis, in turn, the embryonic (embryonic) and fetal (fetal) periods are distinguished. The first lasts 2 months, the second - from the 3rd to the 9th inclusive (Fig. 1).
In the embryonic period, there is an increase in the number of cells that gradually differentiate into the rudiments of all types of tissues (histogenesis). During the second month of intrauterine development, organs are formed (organogenesis); in basic terms, body parts are formed: head, neck, torso and limbs. From the 3rd month, intensive growth and development of the fetal body begins, continuing after the birth of the child.
The process starts from the moment of birth. independent living individual and his adaptation to the environment. Newly acquired traits are superimposed on those inherited, as a result of which complex transformations occur in the body. The physical development of an individual is characterized by weight, height and size of individual parts of the body (Fig. 2).
These indicators change unevenly throughout life. Accelerated growth is observed during early childhood (from 1 year to 3 years), at the age of 5 to 7 years and during puberty (from 11-12 to 15-16 years), while the main proportions of the body also change. In parallel with growth, age-related changes are observed in all organs and systems. Approximately by the age of 20-25, human growth stops and a relatively stable period of existence begins - mature age. After 55-60 years, a person begins to gradually age, and sclerotic changes occur in a number of organs. This in turn causes a decrease in various functions of the body.
From the moment of birth, the process of independent life of the individual and its adaptation to the environment begins. Newly acquired traits are superimposed on those inherited, as a result of which complex transformations occur in the body. The physical development of an individual is characterized by weight, height and size of individual parts of the body (Fig. 2). These indicators change unevenly throughout life.
Accelerated growth is observed during early childhood (from 1 year to 3 years), at the age of 5 to 7 years and during puberty (from 11-12 to 15-16 years), while the main proportions of the body also change. In parallel with growth, age-related changes are observed in all organs and systems. Approximately by the age of 20-25, human growth stops and a relatively stable period of existence begins - mature age. After 55-60 years, a person begins to gradually age, and sclerotic changes occur in a number of organs. This in turn causes a decrease in various functions of the body.
In the process of development and growth of the organism and the formation of its nervous system, the nature and level of human needs change. The newborn is dominated by vital needs associated with the implementation of vital functions: nutrition, respiration, sleep, etc. Gradually, various physiological needs are formed and intensively develop, associated with movement in space, with the assimilation of various nutrients, growth and development, as well as independent performance and arbitrary regulation of physiological functions. Relatively early, already in the first year of life, cognitive needs begin to form, especially during early childhood (1-3 years) and later during the preschool and school periods of a child's development. The formation of social and communicative needs takes a rather long period of ontogeny, including the mature life of an individual.
During puberty, social and communicative needs dominate in the development of the subject's personality. The pinnacle in personal development is the creative needs associated with the accumulation of new knowledge and cultural values. The beginning of the formation of these needs should be attributed to the end of early childhood and the transition to the preschool period of development. However, they can become the dominant motivational basis later, when a person's personality has already been formed, and a period of mature existence begins.
development after birth.
Option 1
A1. What grows most rapidly in a child at the age of 7-10 years?
1) head
2) hands
3) legs
4) torso
A2. How many times longer are the legs of an adult than a newborn?
1) 5 times 3) 3 times
2) 4 times 4) 2 times
A3. What indicates the onset of the biological maturity of young men?
1) the appearance of clumsiness and sweeping movements
2) the appearance of menstruation
3) the appearance of wet dreams
4) accelerated growth of hands
A4. What reflects the degree of physical development of the subject?
1) calendar age
2) biological age
3) a person's inner feeling of his age
4) the age at which the person looks
IN 1. What part of the embryo's body grows faster in the first month of development?
C1. Why does the head grow the fastest in the first month of development in the embryo?
Individual development of the organism. Intrauterine development of the organism.
development after birth.
Option 2
A1. When is the human physique finally formed?
1) during adolescence
2) at the age of 18
3) at 20 years old
4) at the age of 30
A2. How many times larger is an adult's head than a newborn's?
1) 4.5 times
2) 4 times
3) 3 times
4) 2 times
A3. What indicates the onset of the biological maturity of girls?
1) accelerated leg growth
2) the appearance of wet dreams
3) the appearance of menstruation
4) breast growth
A4. When do vasoconstrictor reflexes start to work in a child, and chest breathing is replaced by chest breathing?
1) at 3 years old
2) after a half-height jump (5-7 years)
3) at 7-10 years old
4) in adolescence
IN 1. Where does the fertilization of the egg take place?
________________________________________________________________________
IN 2. How many weeks does a human pregnancy last?
________________________________________________________________________
C1. What is a half-height jump?
Homework: study the text of the paragraph, answer the questions.
Prepare messages: "The influence of bad habits on the development of the fetus"
"The influence of alcohol, smoking and drug addiction on postembryonic development"
Questions for reckoning:
The group is divided into two options, each option is offered 10 test and one theoretical question.
Option 1
1. What is the name of the set of chromosomes characteristic of the species?
2. What is the set of chromosomes in somatic and germ cells?
3. How many chromosomes and DNA are there in different periods of interphase?
4. What are the paired, identical chromosomes of a somatic cell called?
5. What are the names of the primary constriction and the ends of the chromosome?
6. How many chromosomes and DNA are there in a cell before mitosis and at the end of mitosis?
7. How many chromosomes and DNA are there in prophase, metaphase and anaphase of mitosis?
8. What is the meaning of meiosis?
9. What are the names of the first and second divisions of meiosis?
10. What processes occur in the cell in prophase I of meiosis?
11. How many chromosomes and DNA before meiosis, after the first and second divisions?
12. What is the set of chromosomes and DNA in metaphase I and anaphase I of meiosis?
15. When does recombination of genetic material occur in meiosis?
16. List the phases of meiosis, during which the chromosomes are two-chromatid.
18. What is the name of the division, in which multiple division of the nucleus occurs and several individuals are formed (in trypanosomes, malarial plasmodium)?
19. What is characteristic of the genotypes of daughter individuals in comparison with the maternal one during asexual reproduction?
20. What set of chromosomes do spores have?
21. What is the name of the shell of the egg of mammals?
22. When does human oogenesis begin?
23. What is the name of reproduction, in which the development of a new organism occurs from an unfertilized egg?
24. What is the set of chromosomes of gametogonia, gametocytes of the 1st order, gametocytes of the 2nd order?
25. What is formed after spermatogenesis from one spermatocyte?
26. What is formed after oogenesis from one oocyte?
27. What organisms have external fertilization?
28. What are the male and female gametophytes of flowering plants?
29. What is formed from the integuments and the central cell of the embryo sac?
30. What is the pericarp formed from?
31. Who discovered double fertilization?
32. From what periods does the ontogeny of animals develop?
33. What are the periods of animal embryogenesis?
34. What is formed as a result of zygote cleavage?
35. What is the name of the two-layer embryo of the lancelet?
36. What is formed from the ectoderm, endoderm and mesoderm of the neurula?
37. What germ layers form the spine, epidermis and lungs?
38. What animals are deuterostomes?
39. Name three animals with direct postembryonic development.
40. Name three animals with indirect postembryonic development.
Theoretical questions
1. Mitotic cell cycle.
2. Draw and explain the behavior of a pair of homologous chromosomes in prophase, metaphase, anaphase and telophase of the first meiotic division.
Option 2
1. What is formed after spermatogenesis from one spermatocyte?
2. What animals are deuterostomes?
3. What is formed from the integuments and the central cell of the embryo sac?
4. What is the name of the set of chromosomes characteristic of the species?
5. How many chromosomes and DNA are there in different periods of interphase?
6. How many chromosomes and DNA are there in prophase, metaphase and anaphase of mitosis?
7. What is the name of the two-layer lancelet embryo?
8. What is the meaning of meiosis?
9. What processes occur in the cell in prophase I of meiosis?
10. How many chromosomes and DNA before meiosis, after the first and second division?
11. What is the set of chromosomes and DNA in metaphase I and anaphase I of meiosis?
12. What is the pericarp formed from?
13. What is characteristic of the interphase between the first and second divisions of meiosis?
14. What is the set of chromosomes and DNA in metaphase II and anaphase II of meiosis?
15. What is formed after oogenesis from one oocyte?
16. What are paired, identical chromosomes of a somatic cell called?
17. What is characteristic of asexual reproduction?
18. What are the periods of animal embryogenesis?
19. How many chromosomes and DNA are there in a cell before mitosis and at the end of mitosis?
20. What is the name of the division, in which multiple division of the nucleus occurs and several individuals are formed (in trypanosomes, malarial plasmodium)?
21. What is characteristic of the genotypes of daughter individuals in comparison with the maternal one during asexual reproduction?
22. What germ layers form the spine, epidermis and lungs?
23. What set of chromosomes do spores have?
24. What are the membranes of the egg cell of mammals called?
25. What is the name of the primary constriction and the ends of the chromosome?
26. When does human oogenesis begin?
27. Name three animals with indirect postembryonic development.
28. What is the name of reproduction, in which the development of a new organism occurs from an unfertilized egg?
29. What is the set of chromosomes of gametogonia, gametocytes of the 1st order, gametocytes of the 2nd order?
30. What is the set of chromosomes in somatic and germ cells?
31. What organisms have external fertilization?
32. What are the male and female gametophytes of flowering plants?
33. Who discovered double fertilization?
34. From what periods does the ontogeny of animals develop?
35. List the phases of meiosis, during which the chromosomes are two-chromatid.
36. What is formed as a result of zygote cleavage?
37. What are the names of the first and second divisions of meiosis?
38. What is formed from the ectoderm, endoderm and mesoderm of the neurula?
39. When does recombination of genetic material occur in meiosis?
40. Name three animals with direct postembryonic development.
Theoretical questions
1. The mitotic cycle of the cell.
2. Draw and explain the behavior of a pair of homologous chromosomes in prophase, metaphase, anaphase and telophase of the first meiotic division.
3. Asexual reproduction and its forms.
4. Eggs, sperm. Gametogenesis.
5. Types of ontogenesis. Embryogenesis stages.
6. Formation of spores and gametes in flowering plants. Double fertilization.
The period of existence of a cell from the moment of its formation by division of the mother cell (including division itself) to its own division or death is called life (cell) cycle.
The duration of the life cycle in different cells of a multicellular organism is different. Thus, the cells of the nervous tissue after the completion of the embryonic period cease to divide and function throughout the life of the organism, and then die. The cells of the embryo at the stage of crushing, having completed one division, immediately proceed to the next, bypassing all other phases.
Mitosis- indirect division of somatic cells, as a result of which doubling first occurs, and then a uniform distribution of hereditary material between daughter cells.
Biological significance of mitosis: As a result of mitosis, two cells are formed, each of which contains the same number of chromosomes as there were in the mother. Daughter cells are genetically identical to the parent. As a result of mitosis, the number of cells in the body increases, which is one of the main mechanisms of growth. Many plant and animal species reproduce asexually by mitotic cell division alone, thus mitosis is the basis of reproduction. . Mitosis ensures the regeneration of lost parts and cell replacement, which occurs to one degree or another in all multicellular organisms.
Mitotic cycle-consists of interphase and mitosis. The duration of the mitotic cycle varies greatly in different organisms. Direct cell division usually takes 1-3 hours, that is, the main part of the cell's life is in interphase.
Interphase called the interval between two cell divisions. The duration of interphase, as a rule, is up to 90% of the entire cell cycle. Consists of three periods: presynthetic, or G 1 ; synthetic, or S, postsynthetic, or G 2 .
The initial segment of the interphase - presynthetic period(2n2c, where n is the number of chromosomes, c is the amount of DNA), period of growth beginning immediately after mitosis. synthetic period. The duration of the synthetic period is different: from several minutes in bacteria to 6-12 hours in mammalian cells. During the synthetic period, the most important event of interphase occurs - the duplication of DNA molecules. Each chromosome becomes two-chromatid, and the number of chromosomes does not change (2n4c).
post-synthetic period. Provides preparation of the cell for division and is also characterized by intensive processes of protein synthesis that make up the chromosomes; enzymes and energy substances necessary to ensure the process of cell division are synthesized.
Mitosis. For the convenience of studying the events occurring during division, mitosis is artificially divided into four stages: prophase, metaphase, anaphase, telophase.
Prophase(2n4c). As a result of spiralization, the chromosomes are compacted and shortened. In late prophase, it is clearly seen that each chromosome consists of two chromatids connected by a centromere. Chromosomes begin to move towards the cell equator. The spindle is formed, the nuclear membrane disappears, and the chromosomes are freely located in the cytoplasm. The nucleolus usually disappears a little earlier.
metaphase(2n4c). Chromosomes line up in the plane of the equator, forming the so-called metaphase plate. The centromeres of chromosomes lie strictly in the plane of the equator. The spindle threads are attached to the centromeres of the chromosomes, some threads pass from pole to pole of the cell without attaching to the chromosomes.
Anaphase(4n4c). It begins with the division of the centromeres of all chromosomes, as a result of which the chromatids turn into two completely separate, independent daughter chromosomes. Then the daughter chromosomes begin to diverge towards the poles of the cell.
Telophase(2n2c). Chromosomes are concentrated at the poles of the cell and despiralized. The spindle of division is destroyed. A shell of the nuclei of daughter cells is formed around the chromosomes, then the division of the cytoplasm of the cell (or cytokinesis) occurs.
When animal cells divide, a furrow appears on their surface in the equatorial plane, which, gradually deepening, divides the mother cell into two daughter cells. In plants, division occurs by the formation of a so-called cell plate that separates the cytoplasm. It arises in the equatorial region of the spindle, and then grows in all directions, reaching the cell wall.
© Fixing. Conversation. The work of students with a notebook and a codegram.
© Homework .
| |
Lesson 2. Meiosis
Tasks. To form knowledge about the features of the formation of germ cells with a haploid set of chromosomes, about the uniqueness of gametes and the mechanisms of recombination of genetic material during meiosis, about the similarities and differences between meiosis and mitosis, about the need to protect natural environment from mutagen contamination.
Repeat the morphology of chromosomes, the mitotic cycle and the processes occurring in different periods of the mitotic cycle, the significance of mitosis.
Equipment. Demo material: tables on general biology, filmstrip "Cell division", codogram.
During the classes:
© Repetition.
Written work with cards for 10 min.
1. Characteristics of the interphase.
2. Characteristics of mitosis.
3. Morphology of chromosomes.
Working with a card at the blackboard: Appendix 2.
Computer testing: appendix 3.
oral repetition.
© Learning new material: explanation using a filmstrip.
1. The first division of meiosis.
Meiosis is the main stage in the formation of germ cells. During meiosis, there is not one (as in mitosis), but two successive cell divisions. The first meiotic division is preceded by interphase I - the phase of cell preparation for division, at which time the same processes occur as in the interphase of mitosis.
The first meiotic division is called reduction, since it is during this division that a decrease in the number of chromosomes occurs, two cells are formed with a haploid set of chromosomes, but the chromosomes remain two-chromatid. Immediately after the first division of meiosis, the second division takes place - according to the type of ordinary mitosis. This division is called equational, since during this division, the chromosomes become single chromatid.
The biological significance of meiosis: due to meiosis, a reduction in the number of chromosomes occurs. From one diploid cell, 4 haploid cells are formed. Thanks to meiosis, genetically different gametes are formed, because. in the process of meiosis, the recombination of genetic material occurs three times: due to crossing over; random and independent divergence of homologous chromosomes, and then chromatids. Meiosis maintains the constancy of the diploid set of chromosomes in somatic cells.
I and II divisions of meiosis consist of the same phases as mitosis, but the essence of changes in the hereditary apparatus is different.
Prophase I.(2n4c). The longest and most complex phase of meiosis. Consists of a number of successive stages. Homologous chromosomes begin to be attracted to each other by similar regions and conjugate. conjugation called the process of close convergence of homologous chromosomes. A pair of conjugating chromosomes is called bivalent. Bivalents continue to shorten and thicken. Each bivalent is formed by four chromatids. Therefore it is called tetrad. The most important event is crossing over- exchange of parts of chromosomes. Crossing over leads to the first recombination of genes during meiosis. At the end of prophase I, the nuclear envelope and nucleolus disappear. Bivalents move to the equatorial plane. Centrioles (if any) move to the poles of the cell, and the spindle is formed.
Metaphase I(2n; 4s). The formation of the fission spindle is completed. Spiralization of chromosomes is maximum. Bivalents are located in the plane of the equator. Moreover, the centromeres of homologous chromosomes are facing different poles of the cell. The location of bivalents in the equatorial plane is equally probable and random, that is, each of the paternal and maternal chromosomes can be turned towards one or the other pole. This creates prerequisites for the second gene recombination during meiosis. The spindle fibers are attached to the centromeres of chromosomes.
Anaphase I(2n; 4s). Whole chromosomes diverge to the poles, not chromatids, as in mitosis. Each pole has half of the chromosome set. Moreover, pairs of chromosomes diverge as they were located in the plane of the equator during metaphase. As a result, a wide variety of combinations of paternal and maternal chromosomes arise, and a second recombination of genetic material occurs.
Telophase I(1n; 2s). In animals and some plants, the chromatids despiralize and a nuclear membrane forms around them. Then the cytoplasm divides (in animals) or a separating cell wall is formed (in plants). In many plants, a cell from anaphase I immediately transitions to prophase II.
2. The second division of meiosis.
Interphase II(1n; 2s). It is characteristic only for animal cells. DNA replication does not occur.
The second stage of meiosis also includes prophase, metaphase, anaphase, and telophase. It proceeds in the same way as normal mitosis.
Prophase II(1n; 2s). Chromosomes spiralize, the nuclear membrane and nucleoli are destroyed, centrioles, if any, move to the poles of the cell, and a division spindle is formed.
Metaphase II(1n; 2s). The metaphase plate and spindle are formed, and the filaments of the spindle are attached to the centromeres.
Anaphase II(2n; 2s). The centromeres of the chromosomes divide, the chromatids become independent chromosomes, and the spindle fibers stretch them to the poles of the cell. The number of chromosomes in a cell becomes diploid, but a haploid set is formed at each pole. Since in metaphase II the chromatids of chromosomes are randomly located in the plane of the equator, the third recombination of the genetic material of the cell occurs in anaphase, since as a result of crossing over the chromatids began to differ from each other and daughter chromatids move to the poles, but different from each other.
Telophase II(1n; 1s). The fission spindle threads disappear, the chromosomes despiralize, the nuclear envelope around them is restored, and the cytoplasm divides. Thus, as a result of two successive divisions of meiosis, a diploid cell gives rise to four daughter, genetically different cells with a haploid set of chromosomes.
© Anchoring. Conversation. The work of students with a notebook and a codegram.
© Homework assignment. Read the paragraph and answer the questions.
Appendix 1. Codegram. Appendix 2 Cards at the blackboard.
Appendix 3. Computer testing.
Task 14. "Mitosis".
Test 1. Doubles the amount of DNA in a cell:
1. In the presynthetic period.
2. In the synthetic period.
4. In metaphase.
Test 2 Active cell growth occurs:
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
Test 3. The cell has a set of chromosomes and 2n4c DNA and is preparing to divide:
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
Test 4 Chromosome spiralization begins, the nuclear envelope dissolves:
1. In anaphase.
2. In prophase.
3. In telophase.
4. In metaphase.
Test 5 Chromosomes line up along the equator of the cell.
Lesson time- 90 min.
Location- classroom
Class type- seminar session
Lesson objectives:
- Tutorial:
Summarize the knowledge of students on the studied material, skills, abilities; assess the level of knowledge; to control knowledge, skills, abilities; organize knowledge.
- Developing:
To teach to analyze, highlight the main thing, develop professional skills
- Educational:
Education of perseverance and determination in achieving the goal, confidence in knowledge, develop the ability to think; fostering a culture of communication, curiosity, objectivity.
- methodical
Activate cognitive activity students by solving the tasks assigned to them.
Tasks:
1. The development of the student's speech, logical thinking and attention, the ability to analyze, compare, highlight the main thing.
2. education of a value attitude to life, the value of practical knowledge.
3. deepening students' knowledge of this material, enhancing cognitive activity.
Work form: individual, group.
Qualifications
To knowledge:
Students should know the material on the topics: "Properties of living organisms", "Cell", "Cell division", "Mitosis", "Meiosis".
For skills:
Students should be able to freely navigate the material of the topics studied.
Compare knowledge and find solutions.
Draw conclusions, conclusions, justify your point of view.
Interdisciplinary connections:Anatomy, psychology, medicine.
Internal connections: Topics: "Properties of living organisms", "Cell", "Cell division", "Mitosis", "Meiosis", "Fertilization", "Forms of reproduction of organisms"
Equipment: illustrative material, video program, multimedia complex, light microscopes, magnetic board, micropreparations "Mitosis in an onion root", "Ovum division".
Equipment:
- multimedia complex
- Didactic material: cards
- Literature:
Main literature
Internet resources:
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1. Russian State Library [Electronic resource] / Center inform. RSL technologies; ed. Vlasenko T.V. ; Web-master Kozlova N.V. — Electron. Dan. — M.: Ros. state library, 1997—access mode: http://www.rsl.ru, free. — Zagl. from the screen. - Yaz. Russian, English 2. A selection of Internet materials for biology teachers in various biological disciplines [Electronic resource] / NPB im. K.D. Ushinsky RAO - Access mode: http://www.gnpbu.ru 3. A single collection of digital educational resources [Electronic resource] / 2006-2012 FGAU GNII ITT "Informika" 4. Site for teachers of students [Electronic resource] / Publishing House "First of September" - Access mode: http://1september.ru, free. - Zagl. From the screen. - Yaz. Russian 5. Personal website of biology teacher Kapshuchenko A.N. [Electronic resource] free. - Zagl. From the screen. - Yaz. Russian |
Rationale for the topic
The topic "Mitosis" is one of the key topics of biology. It links most sections of biology into a single whole. It is the key to the study of such topics as "Fertilization", "Embryonic development", "Ontogeny", "Patterns of inheritance of traits", "Variability" and others. The topic is directly related to the study of a number of medical sciences: obstetrics, gynecology, anatomy, physiology, medical genetics, psychology.
Allows you to consider a number of social aspects, prospects and achievements modern science. Aim students to study subsequent biology topics. Determine interdisciplinary connections.
Lesson plan
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№ |
Lesson stage |
Time |
Activity |
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teacher |
student |
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Organizational |
Announcement of the topic, objectives of the lesson |
Greets students, organizes attention, communicates the topic and purpose of the lesson. |
Greet the teacher |
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Assessing the readiness of the audience and students |
Checks those present |
Participate in roll call |
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Description of the order of the seminar. |
Explains the procedure for conducting a seminar, the evaluation criteria for a practical lesson. Clarifies the issues that caused difficulties, gives explanations |
Listen carefully and ask questions |
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Systematization of knowledge |
Frontal survey |
Asking questions |
Answer questions |
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Control of knowledge and skills. |
Characteristics of the procedure practical work |
Explains the order of tasks, controls the implementation, gives explanations, individual consultations |
Do the job |
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The final stage |
Generalization, conclusions |
Analysis of the achievement of the goal. Evaluation of students' work. |
Listen, analyze, evaluate their work |
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Answers to students' questions |
Answers students' questions, gives necessary explanations |
Asking questions, listening to answers |
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Total |
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Attachment 1.
Questions for frontal survey
- What are the types of cell division?
- How is amitosis different from other types of cell division?
- What is mitosis? What is its biological meaning?
- What processes take place in the nucleus during interphase?
- Why do chromosomes consist of two chromatins at the beginning of mitosis?
- What changes occur during the prophase of mitosis in the nucleus?
- What part of the chromosome is attached to the spindle thread?
- What is characteristic of the metaphase of mitosis?
- Why is telophase called "prophase in reverse"?
- What chromosomes diverge to the poles of the cell in anaphase?
- What are the chromosomes at the beginning of interphase?
- How many cells and with what set of chromosomes are formed as a result of mitosis?
- What cells are characterized by mitosis?
- What chromosomes are called homologous?
- What is characteristic of prophase?
- How many cells result from mitosis?
- What is the difference between mitosis and meiosis?
Appendix 2
- Repetition of the material covered. The following terms are written on the board:
- Centriole
- replication
- cell cycle
- Chromatin
- Chromatids
- Chromosomes
- Centromere
- Interphase
Students are invited to answer the following questions and choose the correct answer by writing it in the form of a digital version:
- What is the name of the complex consisting of DNA and proteins - histones?
- What is the name of the structure formed before nuclear fission?
- What is the period before nuclear fission called?
- What is the name of the site where the spindle fibers are attached?
- What is the name of the structure of the cell center?
- What is the process of duplicating a DNA molecule called?
- What is the period in the life of a cell from its formation to division into daughter cells called?
- What is the name of one of the two nucleoprotein filaments formed when chromosomes are duplicated?
Annex 3
- Determining the time and place of mitosis in the cell cycle.
On the magnetic board there is an image of the cell cycle, the "mitosis" section is highlighted, the average time is determined: interphase lasts 10 - 20 hours, mitosis 1 - 2 hours. It is also possible to determine the genetic material before division. Mitosis is followed by cytokinesis.
- Definition of mitosis
“mitosis (from Gr. - mitosis - thread) is an indirect division of the cell nucleus and its body, during which each of the two emerging cells receives genetic material identical to the original cell.” Synonyms for nuclear fission is - karyokinesis (translated from gr. karyon - nut, nut kernel, kinesis - movement)
- Phases of mitosis: prophase, metaphase, anaphase, telophase, and then cytokinesis follows (work in a notebook)
Appendix 4
- Student laboratory work. Task: each group receives an envelope containing information about each phase of mitosis, in addition to illustrated material. Considering micropreparations, find a certain phase according to the description, add a certain text from the fragments, stick it on a sheet of paper.
1 group. Prophase.
Chromatids shorten and thicken. The chromatids are clearly visible. Centromeres are not detected. The centrioles move apart at the poles. A microtubule star begins to form. The nucleoli are reduced. By the end of prophase, the nuclear membrane disintegrates and the spindle is formed.
2 group. Metaphase.
Pairs of chromatids are attached by their centromeres to the filaments of the spindle of division and move up and down the spindle until their centromeres line up along the equator of the cell.
3rd group. Anaphase.
Short stage. Each centromere splits into two, and the spindle filaments pull off the daughter centromeres with the opposite pole. Centromeres pull the chromatids separated from each other, now called chromosomes.
4 group. Telophase.
Chromosomes reach the poles of the cell, despiralize, elongate, indistinguishable spindle threads are destroyed, centrioles replicate. A nuclear membrane forms around the chromosomes. The nucleolus appears.
5 group. Cytokinesis.
Following telophase and leading to the first period of interphase, the organelles are distributed among the daughter cells. As a result, two cells are formed with a set of chromosomes identical to the parent.
- Students present their work on the board and show the phase of mitosis on the screen of the multimedia complex.
- Interactive part ( computer program)
- Illustrated material for the video.
Mitosis underlies the growth, regeneration, and vegetative reproduction of all eukaryotic organisms. Further, we will see how this happens at the moment of crushing a fertilized egg - the process that underlies the formation of a multicellular embryo (demonstration of a micropreparation "crushing an egg" on an electron and light microscope).
- Demonstration of the video fragment "Mitosis"
- Mitosis is a very significant process, a lot of effort and time has been spent by scientists to understand all the features of this process. For example, it was found that mitosis in plant and animal cells proceeds with certain differences, that there are factors that adversely affect its course. In addition, in the literature you can see another form of division - direct or amitosis. Work with additional literature.
Group 1: task "Amitosis"
Select "reference" points from the text, i.e. in 4-5 positions indicate the main signs of amitosis. “Mitosis is the most common, but not the only type of cell division. Almost all eukaryotes have the so-called direct nuclear fission, or amitosis. During amitosis, there is no condensation of chromosomes and no spindle is formed, and the nucleus is divided by constriction or fragmentation, remaining in the interphase state. Cytokinesis always follows nuclear division, resulting in the formation of a multinucleated cell. Amitotic division is typical for cells that complete development: dying epithelial, follicular cells of the ovaries ... Amitosis also occurs in pathological processes: inflammation, malignant neoplasm ... after it, cells are not capable of mitotic division.
Group 2: task "violation of mitosis"
Make logical pairs: type of impact - consequences.
“The correct course of mitosis can be disturbed by various external factors: high doses of radiation, certain chemicals. For example, under the influence of X-rays, the DNA of the chromosome can break, and the chromosomes also break. Such chromosomes are not able to move, for example, in anaphase. Some chemicals that are not characteristic of living organisms (alcohols, phenols) disrupt the coordination of mitotic processes. Some chromosomes move faster, others slower. Some of them may not be included in child kernels at all. There are substances that prevent the formation of fission spindle filaments. They are called cytostatics, for example, colchicine and colcemide. By acting on the cell, division can be stopped at the prometaphase stage. As a result of such an impact, a double set of chromosomes appears in the nucleus.
Group 3: task:
Restore the chronological sequence of studying the cell, including the processes of mitosis. Answer in the form of a table:
“The study of the cell began with the invention of the microscope. The first to appreciate the great importance of this device was the English physicist and botanist Robert Hooke. He introduced the term "cell" (1665). Ideas about the self-reproduction of cells developed among biologists by the middle of the 19th century. In 1838 - 39, the botanist Schleiden and the zoologist Schwann combined the ideas of various scientists and formed a cellular theory that postulated "the basic unit of structure and function of living organisms is the cell." Somewhat earlier, the nucleus was discovered by Robert Brown, he described this structure as a characteristic spherical body found in plant cells. In 1868, Haeckel established that the nucleus carries out the storage and transmission of hereditary traits. Ten years earlier, Rudolf Virchow had expanded cell theory by declaring "every cell is from a cell." In 1879, Boveri and Fleming described events occurring in a cell that resulted in the formation of two identical cells.
4 group. Task: "The difference between mitosis in plants and animals."
After analyzing the text, find the differences in the course of mitosis in plants and animals. Fill the table.
The most important event that occurs during mitosis is the even distribution of duplicated chromosomes between two daughter cells. Mitosis in plant and animal cells proceeds almost in the same way, but there are still differences. So, for example, in plant cells there are no centrioles. At the end of the telophase in plant cells, a phragmoplast is formed from the fission spindle filaments in the equatorial part, and ribosomes, mitochondria, and EPS move to the same area. All this leads to the formation of a cell plate, which subsequently divides the cell in two. This process is not observed in animals. There are also differences in cytokinesis, for example, constriction is formed only in animals. Mitoses in animals occur in various tissues and parts of the body, which cannot be said about plants. There, mitosis occurs in strictly defined places where the educational tissue is located, that is, in the meristems. For example, at the tips of the root (growth zone), in the kidney (growth cone), cambium.
5 group. Task: create a symbolic sign that would fit the topic of our lesson. Work in a notebook and on a sheet of paper using colored pencils.
- Student performances.
- Conclusions.
Today's lesson was dedicated to critical process- mitosis. We devoted enough time to the process itself, its features and problems. Most importantly, this process ensures the genetic stability of the species, as well as the processes of regeneration, growth, and asexual (vegetative) reproduction. The process is complex, multistage and very sensitive to environmental factors.
Appendix 5
- Brainstorming (consolidating the studied material)
|
№ |
The cell and its phases |
total weight all DNA molecules |
Number of chromosomes |
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In one non-dividing somatic cell |
6*10-9mg |
46 |
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In one somatic cell at the end of interphase, before prophase |
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In the maternal somatic cell in its prophase and metaphase of mitosis |
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Maternal somatic cell in anaphase |
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In one daughter somatic cell at the end of the telophase of mitosis |
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In two daughter somatic cells (sum) at the end of the telophase of mitosis |
Appendix 5
Testing: "Mitosis"
1. During what period of the mitotic cycle does the amount of DNA double?
2. In the synthetic period.
4. In metaphase.
2. During what period does active cell growth occur?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
3. At what period of the life cycle does a cell have a set of chromosomes and 2n4c DNA and is preparing for division?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
4. During what period of mitosis does the spiralization of chromosomes begin, does the nuclear membrane dissolve?
1. In anaphase.
2. In prophase.
3. In telophase.
4. In metaphase.
5. During what period of mitosis do chromosomes line up along the equator of the cell?
1. In prophase.
2. In metaphase.
3. In anaphase.
4. In telophase.
6. During what period of mitosis do chromatids move away from each other and become independent chromosomes?
1. In prophase.
2. In metaphase.
3. In anaphase.
4. In telophase.
*7. In what periods of mitosis is the number of chromosomes and DNA equal to 2n4c?
1. In prophase.
2. In metaphase.
3. In anaphase.
4. In telophase.
8. In what period of mitosis is the number of chromosomes and DNA equal to 4n4c?
1. In prophase.
2. In metaphase.
3. In anaphase.
4. In telophase.
9. What is the name of the inactive part of DNA in a cell?
1. Chromatin.
2. Euchromatin.
3. Heterochromatin.
4. All DNA in the cell is active.
*10. At what periods of the cell cycle is the number of chromosomes and DNA in a cell equal to 2n4c?
1. In the presynthetic period.
2. At the end of the synthetic period.
3. In the post-synthetic period.
4. In prophase.
5. In metaphase.
6. In anaphase.
7. In telophase.
There are several correct answers to the question.
Answers on the topic "Mitosis":
Test 1. 2.
Test 2. 1.
Test 3. 3.
Test 4. 2.
Test 5. 2.
Test 6. 3.
*Test 7. 1, 2.
Test 8.3.
Test 9.3.
*Test 10. 2, 3, 4, 5.
Task 1 Structure of chromosomes
When are chromosomes visible in the nucleus of a cell?Task 2 Cell life cycle
Look at the picture and answer the questions:
What periods of interphase are indicated by numbers 1 - 3? What is the set of chromosomes and DNA in different periods of interphase? What periods of mitosis are indicated by numbers 4 - 7? What is the set of chromosomes and DNA in different periods of mitosis?
Task 3. Mitotic cycle
Fill the table:
|
periods of interphase and mitosis |
ongoing processes |
Number of chromosomes (n) and the amount of DNA (s) |
|
Presynthetic (G1) Synthetic (S) Postsynthetic (G2) | ||
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metaphase Telophase |
Task 4. Mitotic cycle
Test 1 During what period of the mitotic cycle does the amount of DNA double?
1. In the presynthetic period.
2. In the synthetic period.
4. In metaphase.
Test 2 During what period does cell growth take place?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
Test 3 At what period of the life cycle does a cell have a set of chromosomes and DNA 2n4c and is preparing for division?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
Test 4 During what period of the mitotic cycle does the spiralization of chromosomes begin, the nuclear envelope dissolves?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
Test 5 During what period of the mitotic cycle do chromosomes line up along the equator of the cell?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
Test 6 During what period of the mitotic cycle do chromatids move away from each other and become independent chromosomes?
1. In the presynthetic period.
2. In the synthetic period.
3. In the post-synthetic period.
4. In metaphase.
Test 7 In what periods of mitosis is the number of chromosomes and DNA equal to 2n4c?
1. In prophase.
2. In metaphase.
3. Anaphase.
4. In telophase.
Test 8 At what period of mitosis is the number of chromosomes and DNA equal to 4n4c?
1. In prophase.
2. In metaphase.
3. Anaphase.
4. In telophase.
Test 9 What is the inactive part of DNA in a cell called?
1. Chromatin.
2. Euchromatin.
3. Heterochromatin.
4. All DNA in the cell is active.
Test 10 What are chromosomes called during interphase?
1. Chromatin.
2. Euchromatin.
3. Heterochromatin.
4. Chromosomes.
Task 5. Mitosis
Give answers to the questions:
1. What is a diploid set of chromosomes?
2. What is a haploid set of chromosomes?
3. What is the set of chromosomes and DNA in the presynthetic period of interphase?
4. What is the set of chromosomes and DNA in the postsynthetic period of interphase?
5. What is the set of chromosomes and DNA in the prophase and metaphase of mitosis?
6. What is the set of chromosomes and DNA in the anaphase of mitosis?
7. What is the set of chromosomes and DNA in the telophase of mitosis?
8. How many DNA molecules are in the nucleus of a human somatic cell before mitosis?
9. How many DNA molecules are in the nucleus of a human somatic cell after mitosis?
10. What are the names of chromosomes in the interphase period?
Task 6. Give definitions or expand concepts:
1. Interphase. 2. Chromatin. 3. Chromosome. 4. Chromatids. 5. Centromere. 6. Prophase. 7. Metaphase. 8. Anaphase. 9. Telophase. 10. Diploid set of chromosomes.
Subject: Cell division. Meiosis
Task 7. The first and second divisions of meiosis
Look at the picture and answer the questions:
|
What is the set of chromosomes and DNA in cells before the first division of meiosis? What is the set of chromosomes and DNA in cells at different periods of the first division of meiosis? What is the set of chromosomes and DNA in cells before the second division of meiosis? What is the set of chromosomes and DNA in cells at different periods of the second division of meiosis? At what stage of meiosis do conjugation and crossing of chromosomes take place? In meiosis, the genetic material is recombined three times. When? What is the biological meaning of meiosis?
Task 8. Meiosis
Fill the table:
|
divisions of meiosis |
ongoing processes |
Number of chromosomes (n) and the amount of DNA (s) |
|
Prophase-1 Metaphase-1 Anaphase-1 Telophase-1 | ||
|
Interphase | ||
|
Prophase-2 Metaphase-2 Anaphase-2 Telophase-2 |
Task 9. Meiosis
Specify the correct answers:
Test 1 When does conjugation of homologous chromosomes occur during meiosis?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
Test 2 What is the set of chromosomes and DNA at the end of the 1st division of meiosis?
1. 1n1c. 5. 2n4c.
2. 1n2c. 6.4n4c.
Test 3 What is the set of chromosomes and DNA at the end of the 2nd division of meiosis?
1. 1n1c. 5. 2n4c.
2. 1n2c. 6.4n4c.
Test 4 In what stages of meiosis is the set of chromosomes and DNA 1n4c?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
Test 5 In what stages of meiosis is the set of chromosomes and DNA 2n4c?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
Test 6 In what stages of meiosis is the set of chromosomes and DNA 1n2c?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
Test 7 In what stages of meiosis is the set of chromosomes and DNA 2n2c?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
Test 8 In what stages of meiosis is the set of chromosomes and DNA 1n1c?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
***Test 9. During what stages of meiosis does recombination of genetic material take place?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
Test 10 During what stages of meiosis does crossing over occur?
1. Prophase Prophase 2.
2. MetaphaseMetaphase 2.
3. AnaphaseAnaphase 2.
4. TelophaseTelophase 2.
Task 10. Meiosis
Give answers to the questions:
1. What is the set of chromosomes and DNA before the first division of meiosis?
2. What is the set of chromosomes and DNA before the second division of meiosis?
3. What chromosomes are called homologous?
4. What processes occur in prophase-1 of meiosis?
5. In what phases of the first division of meiosis does the recombination of genetic material occur?
6. What is characteristic of the interphase between the first and second divisions of meiosis?
7. What is the set of chromosomes and DNA in prophase-2 and metaphase-2?
8. In what phase of the second meiotic division does the recombination of genetic material occur?
9. What is the set of chromosomes and DNA at the end of the second meiotic division?
10. How many cells are formed as a result of meiosis from one mother cell?
Task 11. Give definitions or expand concepts:
1. Homologous chromosomes. 2. Conjugation. 3. Crossing over. 4. Diploid set of chromosomes. 5. Haploid set of chromosomes. 6. Reduction division of meiosis. 7. Recombination to anaphaseRecombination to anaphaseBiological meaning of meiosis.
Topic: Asexual and sexual reproduction
Task 12. Various forms of asexual reproduction
Look at the picture and answer the questions:
|
What forms of asexual reproduction are indicated in the figure by numbers 1 - 6? What genetic material do the offspring have during asexual reproduction?
Task 13. Characteristics of various forms of asexual reproduction
Fill the table:
|
Forms of asexual breeding |
Characteristics |
|
1. Asexual reproduction of bacteria 2. Binary division 3. Shizogony 4. Sporulation 5. Budding 6. Fragmentation 7. Vegetative propagation 8. Polyembryony 9. Cloning |
Task 14. Comparison of asexual and sexual reproduction
Fill the table:
|
Comparable Features |
asexual reproduction |
sexual reproduction |
|
1. The number of individuals involved in reproduction 2. Genetic material of offspring 3. Recombination of genetic material 4. Importance for selection |
Task 15. Asexual and sexual reproduction
Specify the correct answers:
Test 1 What form of asexual reproduction is most typical for mosses and ferns?
Test 2 What form of asexual reproduction is most typical for hydra, yeast?
1. Binary division. 5. Cloning.
2. Shizogony. 6. Vegetative propagation.
3. Fragmentation. 7. Polyembryony.
4. Budding. 8. Sporulation.
Test 3 What form of asexual reproduction is used to propagate fruit and berry crops?
1. Binary division. 5. Cloning.
2. Shizogony. 6. Vegetative propagation.
3. Fragmentation. 7. Polyembryony.
4. Budding. 8. Sporulation.
Test 4 What natural form of asexual reproduction is known in humans?
1. Binary division. 5. Cloning.
2. Shizogony. 6. Vegetative propagation.
3. Fragmentation. 7. Polyembryony.
4. Budding. 8. Sporulation.
Test 5 What form of asexual reproduction is typical for planaria, some annelids?
1. Binary division. 5. Cloning.
2. Shizogony. 6. Vegetative propagation.
3. Fragmentation. 7. Polyembryony.
4. Budding. 8. Sporulation.
Test 6 What is characteristic of asexual reproduction?
1. The offspring has the genes of only one, the mother's organism.
2. Offspring are genetically different from parental organisms.
3. One individual participates in the formation of offspring.
4. Two individuals usually participate in the formation of offspring.
Test 7 What form of reproduction allows you to adapt to changing environmental conditions?
1. Asexual reproduction.
2. Sexual reproduction.
3. And asexual and sexual reproduction equally.
4. The form of reproduction does not matter.
**Test 8. Specify the correct statements:
1. Parthenogenesis is a special form of asexual reproduction.
2. Parthenogenesis is a special form of sexual reproduction.
3. Parthenogenetic development is known in aphids, bees, and daphnia.
4. Parthenogenetic development is known in humans.
**Test 9. Specify the correct statements:
1. Hermaphrodites - organisms that can form both male and female gametes.
2. Gametes have a haploid set of chromosomes, the zygote is diploid.
3. developed methods for targeted production of 100% individuals of the same sex.
4. Bacteria divide by mitosis.
**Test 10. Specify the correct statements:
1. Asexual reproduction has no advantages over sexual reproduction.
2. Gametes and zygote have a haploid set of chromosomes.
3. Two individuals always take part in sexual reproduction.
4. Sexual reproduction dramatically increases the hereditary variability of offspring.
Topic: The formation of germ cells and fertilization
Task 16. Gametogenesis
Look at the picture and answer the questions:
1. *** What is indicated in the figure by numbers 1 - 12?
2. What is the size of an egg in humans?
3. What is in the cytoplasm of the egg?
4. Where are the nucleus and mitochondria located in the spermatozoon?
Task 18. Gametogenesis. Fertilization
Specify the correct answers:
Test 1 What set of chromosomes do the precursors of gametes have in the breeding zone?
1. Diploid.
2. Haploid.
3. Spermatogonia are diploid, ovogonia are haploid.
4. Spermatogonia are haploid, ovogonia are diploid.
Test 2 What set of chromosomes do cells have in the maturation zone after the first division of meiosis?
Test 3 What set of chromosomes do gametes have?
Test 4 How many normal eggs are produced from one oocyte after two divisions of meiosis?
Test 5 How many normal spermatozoa are formed from one spermatocyte after two divisions of meiosis?
Test 6 Where is the Golgi complex located in the spermatozoon?
1. In the head.
2. In the neck.
3. In the intermediate department.
4. In the ponytail.
Test 7 Where are the mitochondria located in the sperm?
1. In the head.
2. In the neck.
3. In the intermediate department.
4. In the ponytail.
Test 8 Where are the centrioles located in the spermatozoon?
1. In the head.
2. In the neck.
3. In the intermediate department.
4. In the ponytail.
**Test 9. Specify the correct statements:
1. In the growth zone, the chromosome set is 2n.
2. In the zone of maturation, two divisions of meiosis occur - reduction and equational.
3. During oogenesis, four normal eggs are formed from one oocyte.
4. During oogenesis, one normal egg and four directional (polar) bodies are formed from one oocyte.
***Test 10. Specify the correct statements:
1. The human egg is about 0.1 mm in size.
2. Human eggs are formed at the embryonic stage.
3. The human egg has two shells - shiny and radiant.
4. There are no ribosomes and mitochondria in the human egg.
Topic: Individual development of organisms
Task 19. The main stages of embryogenesis
Look at the picture and answer the questions:
|
*** What is indicated in the figure by the numbers 1 - 10? What is formed as a result of zygote cleavage? *** What is further formed from the blastocoel? What is the name of the hole in the gastrula? What germ layer does the neural tube develop from? What is the name of an embryo with a formed axial complex? What happens if we take a portion of the ectoderm from which the nervous system is formed from one gastrula and transplant it under the abdominal ectoderm of another gastrula?
Task 20. Derivatives of germ layers
Fill the table:
|
germ layers |
Derivatives of the germ layers |
|
ectoderm | |
|
Endoderm | |
|
mesoderm |
Task 21. Ontogeny
Specify the correct answers:
Test 1.What is formed as a result of complete crushing of the zygote?
1. Neirula.
2. Blastula.
3. Gastrula.
4. Morula.
Test 2. What is the name of the cavity inside the blastula?
1. Blastocoel.
2. Gastrocoel.
3. Secondary body cavity.
Test 3. What is the name of a two-layer embryo with germ layers: ectoderm and endoderm?
1. Gastrula.
2. Blastula.
3. Neirula.
4. Morula.
Test 4. What is the name of the cavity into which the primary mouth leads?
1. Blastocoel.
2. Gastrocoel.
3. Secondary body cavity.
4. Mixed body cavity (myxocoel).
Test 5. What organisms are classified as deuterostomes?
1. Coelenterates and sponges.
2. Flat and roundworms.
3. Mollusks and arthropods.
4. Echinoderms and chordates.
Test 6. What is the name of an embryo with an axial complex of organs?
1. Gastrula.
2. Blastula.
3. Neirula.
4. Morula.
Test 7. Specify derivatives of ectoderm:
Test 8. Specify derivatives of endoderm:
1. The epidermis of the skin. 6. Digestive system.
2. Epithelium of the digestive system. 7. Digestive glands.
3. Circulatory system. 8. Respiratory system.
4. Excretory system. 9. Reproductive system.
5. Nervous system. 10. Sense organs.
Test 9. Specify derivatives of mesoderm:
1. The epidermis of the skin. 6. Digestive system.
2. Epithelium of the digestive system. 7. Digestive glands.
3. Circulatory system. 8. Respiratory system.
4. Excretory system. 9. Reproductive system.
5. Nervous system. 10. Sense organs.
Test 10 Specify animals with indirect postembryonic development:
1. Mammals. 5. Butterflies.
2. Birds. 6. Locust.
3. Reptiles. 7. Spiders.
4. Amphibians. 8. Cockroaches.
Task 22. Ontogeny
Biological dictation:
1. What is the name of the individual development of the organism from the formation of a zygote to the end of life?
2. What is the name of the development of the organism from the zygote to birth or to release from the egg membranes?
3. What is the name of the period from birth to the end of life?
4. How does the crushing period end?
5. What is the name of an embryo with three germ layers: ectoderm, endoderm and mesoderm?
6. What organisms are deuterostomes?
7. What is the name of the embryo in which the axial complex of organs has formed?
8. What organ systems are formed from the ectoderm?
9. Specify endoderm derivatives.
10. Write down two types of animals with direct and indirect types of postembryonic development.
Task 23. Give definitions or expand concepts:
1. Fertilization. 2. Zygote. 3. Blastomeres. 4. Blastula. 5. Blastocoel (primary cavity). 6. Gastrula. 7. Mesoderm. 8. Secondary mouth. 9. Neirula. 10. Indirect postembryonic development.
Materials used, Honored School Teacher Russian Federation; , Ph.D.
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