Principles of Inheritance and Variation Question 120
120. In our society women are blamed for producing female children. Choose the correct answer for the sex-determination in humans
[NEET Kar. 2013]
(a) Due to some defect in the women
(b) Due to some defect like aspermia in man
(c) Due to the genetic make up of the particular sperm which fertilizes the egg
(d) Due to the genetic make up of the egg
Show Answer
Answer : c
Hints & Solution
(c) In case of humans, the sex determining mechanism is xy type. Out of 23 pairs of chromosomes, 22 pairs are exactly same in both males and females called autosomes. A pair of $x$ chromosomes is present in the female, whereas the presence of an $x$ and $y$ chromosome are determinant of male characteristic. in case the ovum fertilises with a sperm carrying $x$ chromosome the zygote develops into a female (xx) and the fertilisation of ovum with y chromosome carrying sperm results into a male offspring.
