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प्रश्न
Give scientific reason.
Older women are more likely to give birth to children with some abnormalities.
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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 syndrome) in offspring.
Hence, older women are more likely to give birth to children 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
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Expand the acronym.
LH
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1 primary spermatocyte : 4 spermatozoa :: 1 primary oocyte : ____________.
Identify the diploid cell.
Identify the enzyme released by the sperm which has lytic activity.
Which of the following is diploid?
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How many sperms are formed from 4 primary spermatocytes?
The process of release of spermatozoa from Sertoli cells into cavity of the seminiferous tubules is called ______.
Select the correct sequence of stages of spermatogenesis in a human male ______.
What does the figure represent?
The region of the root tip whose cells undergo rapid elongation and enlargement and are responsible for the growth of the root in length is called the:
Germ cells present in the seminiferous tubules undergo ______
Process of maturation and development of sperms ______.
Meiotic division of the secondary oocyte completed ______.
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