10. Mention the total number of chromosomes along with the sex chromosomes that are present in a human male and human female. “It is a matter of chance whether a couple will have a male or female child.” Justify this statement by drawing a flowchart.
Answers
The sex determination is XY type in humans. There are 23 pairs of chromosomes found in human Out of these, 22 pairs are called autosomes which are same in both male and females. The rest one pair is called six chromosome. These vary in males and females. Males have one X chromosome and one Y chromosome(heterogametic). In contrast, females have two copies of the X chromosome (homogametic). All the haploid gamete produced by the female have X chromosome whereas, the gametes produced by the male have either X or Y chromosome. After fusion of the gametes the formed zygote have either XX or XY chromosome, depending upon whether the X or Y chromosome fertilised the ovum. There is fifty-fifty chance of this. On the basis of this fusion, sex of the child is determined whcih depends on the father not the mother.