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प्रश्न
How many pairs of chromosomes are present in human beings? Out of these how many are sex chromosomes?
उत्तर
- Human beings have 46 chromosomes (23 pairs) in each cell.
- Out of these, two (one pair) are sex chromosomes (XX in females, XY in males).
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संबंधित प्रश्न
Give scientific reasons: When an ovum gets fertilized, menstrual cycle stops temporarily in a woman.
Give scientific reasons: Mature erythrocytes in humans lack nucleus and mitochondria
Give technical terms for Thin walled sac of skin which covers the testes
What do the testes in a man produce?
Describe the process of fertilisation in humans and development of embryo briefly.
In a flower, the parts that produce male and female gametes are respectively :
(a) sepal and anther
(b) filament and stigma
(c) anther and ovary
(d) stamen and style
The diagram below represents two reproductive cells A and B. Study the same and then answer the questions that follow:
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- Identify the reproductive cells A and B.
- Name the specific part of the reproductive system where the above cells are produced.
- Where in the female reproductive system do these cells unite?
- Name the main hormones secreted by the (1) ovary (2) testes.
- Name an accessory gland found in the male reproductive system and state the function of its secretion.
Give appropriate term of the following:
The onset of reproductive phase in a young female.
State the Location:
Prostate gland
