Q. Consider the following statements regarding sex determination in humans:
1.23 pairs of chromosomes present in humans.
2.22 pairs are exactly same in both males and females.
3.A pair of X-chromosomes is present in the male, whereas the presence of an X and Y chromosome are determinant of the female characteristic.
Choose the correct answer from below given codes:

[A] 1 only

[B] 1 and 2 only

[C] 2 and 3 only

[D] 1, 2 and 3

Answer: B
Notes:

Explanation: It has already been mentioned that the sex determining mechanism in case of humans is XY type.

  • Out of 23 pairs of chromosomes present, 22 pairs are exactly same in both males and females; these are the autosomes.
  • A pair of X-chromosomes is present in the female, whereas the presence of an X and Y chromosome are determinant of the male characteristic.

Source: Science NCERT