Question

determined what a baby will be a boy or girl​

Answer 1

this depends upon the chromosomes of the men if the mixing of the chromosomes are same type then it will be a girl otherwise there will be a girl

Answer 2

The process of determination of the sex of a baby is called Sex Determination.

Before answering the question, we need to know a few things.

1. The gametes of both males and females have two sex chromosomes.
2. The male sex chromosomes are XY.
3. The female sex chromosomes are XX.

Now, let's start with the answer.

When the zygote is formed after fertilization of the ovum by the male gamete (sperm), the zygote takes one sex chromosome from the female ovum and one from the male sperm.

Since Females have only XX chromosomes, one chromosome of the zygote is fixed, ie, the X chromosome.

Now, if the other chromosome from the male sperm is X, then the resultant zygote will have the chromosomes XX. So, a girl child will be born.

And, if the other chromosome from the male sperm is Y, then the resultant zygote will have the chromosomes XY. So, a boy child will be born.

This is what sex determination is.