Define Sex determination in the unborn baby.
Answers
Sex determination in the unborn baby: The sex of a child, i.e., whether it is a male or a female is determined at the time of fertilisation when a male gametes fuse with a female gamete. All human beings have 23 pairs of chromosomes in the nuclei of their cells. Two chromosomes out of these are sex chromosomes. A female has two X chromosomes, while a male has one X and one Y chromosome. The gametes (egg and sperm) have only one set of chromosomes. The unfertilised egg always has one X chromosome.
But sperms are of two kinds—One having X chromosome, and the other having Y chromosome. When a sperm containing X chromosome fertilises the egg, the zygote would have two X chromosomes and develop into a female child. If the sperm contributes a Y chromosome to the egg or ovum at fertilisation, the zygote would develop into a male child. It is thus also clear that the sex chromosomes of the father determine the sex of an unborn baby.
Answer:
☞Sex determination in the unborn baby. The sex of the unborn baby is determined by the sex chromosomes of the father. ... An egg will always have an X chromosome. Therefore, if the sperm contributes X chromosome then the baby will be a female (XX) and if the sperm contributes the Y chromosome, the baby will be a male (XY).