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What are the 4 functions of meiosis?
- SILLY GARRY FORGOT ZEBRAS
- 1.Sexual reproduction / gamete formation: as daughter cells are haploid they can combine with similar cells at fertilisation to restore diploid number.
- 2.Genetic variation: crossing over, independent assortment, offspring a mix of different genes.
- 3. Formation of haploid spores: in flowering plants.
- 4. Zygospore germination: development of an active haploid vegetative phase in Rhizopus from the diploid dormant zygospore.
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How is sexual reproduction / gamete formation a function of meiosis?
As the daughter cells have half the number of chromosomes they can combine with similar cells at fertilisation to restore the diploid number.
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How is the diploid number restored?
Sexual reproduction / gamete formation: Haploid daughter cells combine with similar cells at fertilisation to restore the diploid number.
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How is genetic variation a function of meiosis?
- Genetic Variation:
- Crossing over changes the arrangement of genes.
- Independent assortment- a cell with genes AaBb will produce equal numbers of gametes with genes AB, Ab, aB, ab, therefore at fertilisation new genetic combinations may arise.
- In sexual reproduction, variety in offspring is got by mixing the different genes of the two parents.
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What changes the arrangement of genes?
Crossing over changes the arrangement of genes (genetic variation).
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What is independent assortment?
Independent assortment- a cell with the genes AaBb will produce equal numbers of gametes with genes AB, Ab, aB, ab, therefore at fertilisation new genetic combinations may arise.
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How is formation of haploid spores a function of meiosis?
- Flowering plants - pollen mother cells in anther of stamen undergo meiosis forming haploid micro spores from which the sperm / gametes develop by mitosis.
- Embryo sac mother cell in ovule of the carpel undergoes meiosis to form the haploid which develop into the egg and polar nucleus by mitosis.
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In flowering plants what undergoes meiosis?
- Pollen mother cells in anther of stamen undergo meiosis forming haploid microspores
- Embryo sac mother cell in ovule of the carpel undergoes meiosis to form the haploid.
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What is formed when pollen mother cells in anther of stamen undergo meiosis, in flowering plants ?
Pollen mother cells in anther of stamen undergo meiosis forming haploid microspores from which the sperm / gametes develop.
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What are haploid microspores in flowering plants?
Pollen grains
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What is an embryo sac mother cell?
Male sporophyte.
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Where is the embryo sac mother cell situated?
Embryo sac mother cell in ovule of the carpel
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What undergoes meiosis in the ovule of the carpel?
Embryo sac mother cell in ovule of the carpel undergoes meiosis to form the haploid
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How is zygospore germination a function of meiosis?
Zygospore germination: the development of an active haploid vegetative phase in Rhizopus from the diploid dormant zygospore.
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What does meiosis produce in animals?
Meiosis in animals produces gametes.
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What does meiosis produce in plants?
Meiosis in plants produces spores (which later produce gametes).
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Where is the occurrence of meiosis in male mammals?
Testes of male mammals.
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Where is the occurrence of meiosis in female mammals?
Ovaries of the female mammals.
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Where is the occurrence of meiosis in angiosperms?
- Anther of the male (has pollen),
- Ovule of the female.
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What are angiosperms ?
Flowering plants.
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