Why it is scientifically correct to say that sex of the baby is determined by the father and not by the mother ?

Options

A. Human feamle produces two types of gametes
B. Human male produces one type of gametes
C. Human female is XX, whereas male is XY 50 percent of sperms carry the X chromosome while other 50% carry Y chromosome
D. All of these

Answer

To understand why it is scientifically correct to say that the sex of the baby is determined by the father and not by the mother, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Understanding Gametes**:
- In humans, gametes are the reproductive cells that combine during fertilization. Males produce sperm, and females produce ova (eggs).

2. **Sex Chromosomes in Males and Females**:
- Males have two different sex chromosomes: X and Y (XY). This means they are heterogametic, producing two types of sperm: one carrying the X chromosome and the other carrying the Y chromosome.
- Females have two of the same sex chromosome: X and X (XX). This means they are homogametic, producing only one type of ovum, which always carries the X chromosome.

3. **Fertilization Process**:
- During fertilization, the sperm from the father combines with the ovum from the mother.
- If a sperm carrying the X chromosome fertilizes the ovum (which also carries an X chromosome), the resulting zygote will be XX, leading to a female baby (girl).
- If a sperm carrying the Y chromosome fertilizes the ovum, the resulting zygote will be XY, leading to a male baby (boy).

4. **Conclusion**:
- Since the father can contribute either an X or a Y chromosome, and the mother can only contribute an X chromosome, it is the type of sperm that determines the sex of the baby. Thus, it is scientifically correct to say that the sex of the baby is determined by the father.