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: Understanding the Genetic Basis of Sex Determination:
In humans, the sex of the child is determined by the combination of sex chromosomes contributed by the father and the mother.
- The mother always contributes an X chromosome (because females have XX chromosomes).
- The father can contribute either an X chromosome or a Y chromosome (because males have XY chromosomes).

Step 2: Sex Chromosome Combinations:
- If the sperm from the father carries an X chromosome and fertilizes the egg from the mother (which always carries an X chromosome), the resulting child will be female (XX).
- If the sperm from the father carries a Y chromosome and fertilizes the egg, the resulting child will be male (XY).

Step 3: Probability of Male or Female Child:
Since the sperm from the father has an equal chance (50%) of carrying either an X or a Y chromosome, the probability of having a female child (XX) or a male child (XY) is 50% each.

Step 4: Conclusion:
The probability of having a male or a female child is 50%, which is determined by the random combination of the X or Y chromosome from the father with the X chromosome from the mother.