Question

“In human beings, the genes inherited from the parents decide whether the newborn individual is male or female.”

Explain this statement with the help of a flow diagram.

Answer 1

1. In humans, the sex of a child is determined by the type of chromosome inherited from the father. Males have XY chromosomes, and females have XX chromosomes.
2. Most human chromosomes have a maternal and a paternal copy, and we have 22 such pairs. But one pair, called the sex chromosomes, is odd in not always being a perfect pair. Women have a perfect pair of sex chromosomes, both called X. But menhave a mismatched pair in which one is a normal-sized Xwhile the other is a short one called Y. So women are XX, while men are XY. 
3. As Fig. shows, half the children will be boys and half will be girls. All children will inherit an X chromosome from their mother, regardless of whether they are boys or girls. Thus, the sex of the children will be determined by what they inherit from their father. A child who inherits an X chromosome from her father will be a girl, and one who inherits a Y chromosome from him will be a boy.