Question

If the first seven children of a particular pair of the parents are all-male what is the probability that the eighth will be the male:-
A. 1/2
B. 1/4
C. 1/8
D. 1/10

Answer 1

Hint: The male and female of the offspring depend on the 23rd chromosome and X and a Y chromosome. These are known as sex chromosomes.

Complete answer: 1. When a male and female copulate with each other then the probability of boy offspring as well as girl offspring will remain the same because sex chromosomes are not linked with other chromosomes, they are independent.
2. If both the chromosomes have X type than the offspring will be female and if one is X type chromosome and one is Y type chromosome then the offspring will be male
3. Gametes of male parents are X, Y, and gametes of Female parents are X, X.
4. So the offspring of that cross are XX, XY, XX, XY
5. In the first generation two boys and two girls obtain the chances of both boys and girls being the same there is a 50 percent chance of boy and 50 percent chance of girl baby.
6. The first seven offspring sex will not interfere with the sex determination of the eighth offspring whether they are boy or girl it will not affect the sex of the next child.
7. Here the ratio of boys and girls is 1:1 both have the same chances to produce.

So the probability for a boy for an eighth child is 50 percent and 1/2.

Option A is correct.

Note: Humans have 23 pairs of chromosomes for the different characters.
The chances of a male and female child will always remain 50%.