Choose the correct answer:
Which one of the following is true regarding sex determination in human beings?

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

Barr body is usually present in men and absent in women

If the first child of a couple is male, the probability of the second child to be female is 100%.

Sex of the child is determined by the genetic makeup of the sperm.

All the sperms have one set of autosomes and one Y-chromosome.

answer is C.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

During spermatogenesis among males, two types of gametes are produced. 50 per cent of the total sperm produced carry the X-chromosome and the rest 50 per cent have Y-chromosome besides the autosomes. Females, however, produce only one type of ovum with an X-chromosome. In case the ovum fertilises a sperm carrying X-chromosome, the zygote develops into a female (XX) and the fertilisation of ovum by a sperm carrying Y-chromosome results in male offspring (XY). Thus, it is evident that the genetic makeup of the sperm determines the sex of the child. Y chromosome has TDF which determines the male sex. Its absence in zygotes leads to female sex.

Barr body represents inactivated X-chromosome. It is usually present in women but absent in men.

Watch 3-min video & get full concept clarity