What is the probability that a pregnancy would result in a male child?

A.

¾

B.

½

C.

1

D.

¼

Correct answer is B

In humans, the sex of a child is determined by the combination of sex chromosomes received from the parents. The mother contributes an X chromosome, and the father contributes either an X chromosome (resulting in a female child) or a Y chromosome (resulting in a male child).

Since the father can contribute either an X or a Y chromosome, there are two possible outcomes for the sex of the child: male (XY) or female (XX). The chance of having a male child (XY) is equal to the chance of having a female child (XX).
Therefore, the probability of having a male child is 1 out of 2, which is represented as ½.