The sex of child depends upon chromosome present in :

Options

A. Egg of female
B. Sperm of male
C. Both (A) and (B)
D. None of these

Answer

To determine the sex of a child, we need to analyze the chromosomes present in the gametes (sperm and egg) from both parents. Here’s a step-by-step solution:

### Step 1: Understanding Gametes
- Gametes are the reproductive cells that unite during fertilization. In humans, the female gamete is called the ovum (egg), and the male gamete is called the sperm.

### Step 2: Chromosome Composition
- The egg (ovum) always carries an X chromosome. Therefore, the genetic contribution from the mother will always be X.
- The sperm can carry either an X chromosome or a Y chromosome. This means the genetic contribution from the father can be either X or Y.

### Step 3: Fertilization Outcomes
- When fertilization occurs, the combination of the chromosomes from the egg and sperm determines the sex of the child:
- If the sperm carrying an X chromosome fertilizes the egg (which also has an X chromosome), the resulting combination will be XX, which results in a female child.
- If the sperm carrying a Y chromosome fertilizes the egg, the combination will be XY, resulting in a male child.

### Step 4: Conclusion
- Since the sex of the child is determined by the combination of the chromosomes from both the egg and the sperm, the deciding factor for the sex of the child is the sperm. Therefore, the correct answer to the question is that the sex of the child depends upon the chromosomes present in both the egg of the female and the sperm of the male.

### Final Answer
- The sex of the child depends upon the chromosomes present in: **Both A and B (the egg of female and sperm of male)**.

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