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प्रश्न
If newborns are produced at the age of menopause, they may be with some abnormalities. Why?
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उत्तर
- A female has millions of oocytes at the time of birth and new ova are not formed thereafter.
- Menopause occurs at approximately 40-50 years of age and hence fewer numbers of eggs are present with reduced fertility since the oocytes have aged.
- Their ability to divide diminishes and they may not be able to complete meiotic division properly.
- Fertilization of such oocytes may result in the production of genetic abnormalities (like Down’s syndrome) in offsprings.
Hence, if newborns are produced at the age of menopause, they may be with some abnormalities.
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संबंधित प्रश्न
Draw a diagram of the microscopic structure of human sperm. Label the following parts in it and write their functions:
- Acrosome
- Nucleus
- Middle piece
Ovulation is induced by a hormone called ______.
Implantation of embryo occurs in ______.
Body breaks up into several fragments and each fragment starts to live as a new individual. This is ______ type of reproduction.
Explain the structure of secondary oocyte.
Describe the process of spermatogenesis with the help of diagram.
In meiosis, the number of chromosomes becomes ___________.
Give scientific reason.
Older women are more likely to give birth to children with some abnormalities.
In angiosperms, the pollen germinates to produce a pollen tube that carries two gametes. What is the purpose of carrying two gametes when a single gamete can fertilize the egg?
Give a schematic representation of spermatogenesis and oogenesis in humans.
______ undergoes 2nd meiotic division during spermatogenesis.
Select the pair of cells which does not divide further by mitosis.
After ovulation, Graafian follicle regresses into ______.
By which process sperms released from the seminiferous tubules?
Corona radia is made up of ______.
The cell which undergoes meiosis I during spermatogenesis is the ______.
At what stage of life is oogenesis initiated in a human female?
1st polar body is formed at which stage of oogenesis?
What is the difference between a primary oocyte and a secondary oocyte?
Sketch and label the process of oogenesis.
