Question

In human beings, the probability of getting a male or a female child is 50%. Explain with the help of a flow diagram only.

Answer 1

Step 1: Genetic Basis of Sex Determination:
In humans, the father's sperm and the mother's egg determine the child's sex chromosomes.
- The mother always provides an X chromosome (female genotype: XX).
- The father can provide either an X or a Y chromosome (male genotype: XY).

Step 2: Sex Chromosome Combinations and Resulting Sex:
- Egg (X) + Sperm (X) = Female child (XX).
- Egg (X) + Sperm (Y) = Male child (XY).

Step 3: Probability of Child's Sex:
The father's sperm has a 50% chance of carrying an X chromosome and a 50% chance of carrying a Y chromosome. Therefore, the probability of a female (XX) or male (XY) child is 50% for each.

Step 4: Conclusion:
The sex of a child is determined with a 50% probability for male or female based on the random combination of the father's X or Y chromosome with the mother's X chromosome.