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प्रश्न
Explain how the sex of the child is determined at the time of conception in human beings.
उत्तर
Every somatic (body) cell of humans contains 23 pairs of chromosomes. Out of these 23 pairs, the first 22 pairs (44 chromosomes) do not determine the sex of an individual and they are known as autosomes. The remaining one pair determines the sex of the individual. This last pair is known as the sex chromosomes and are represented as X and Y.
The male gametes have 22 autosomes and either an X or a Y sex chromosome.
On the other hand, the females have XX sex chromosomes, along with the 22 autosomes. This means that their gametes can only have an X sex chromosome
Therefore, the sex of the child is determined by the type of the sperm (containing an X or a Y sex chromosome) which fuses with the egg cell (containing an X chromosome) at the time of conception.
If the X gamete of the male fuses with the X gamete of the female, then the offspring will be female.
On the other hand, if the Y gamete of the male fuses with the X gamete of the female, then the offspring will be male.
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संबंधित प्रश्न
Describe placenta structure.
Write the functions of the following parts in human female reproductive system:-
(i) Ovary
(ii) Oviduct
(iii) Uterus
Write the function of the following part in a human female reproductive system:
Fallopian tube
Which part of the human body produces ova?
Which of the following is not a sexually transmitted disease?
(a) gonorrhoea
(b) hepatitis
(c) syphilis
(d) AIDS
Describe in brief the role of vas deferens in human male reproductive system.
Diagram shows the reproductive system of female human beings:
(i) Name the parts numbered 1 to 14.
(ii) Normally, after how many days does an ovary release an egg?
(iii) Where are the sperms released during coitus?
(iv) What is the role of sperms after their ejaculation in vagina?
(v) What is the function of the organ numbered 5?
(vi) What is the gestation period in human?
Define the following:
Gestation
The following is the illustration of the sequence of ovarian events (a-i) in a human female.
Write the difference between C and H.
