Assertion: The presence of X or Y chromosome in the sperm determine the sex of the embryo
Reason: All the eggs have one X chromosome.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that the presence of X or Y chromosome in the sperm determines the sex of the embryo. This is correct because the sex of the embryo is determined by the combination of sex chromosomes contributed by both the sperm and the egg.

2. **Understanding the Reason**: The reason provided states that all the eggs have one X chromosome. This is also correct. In humans, all eggs (ova) produced by females contain one X chromosome, as females have two X chromosomes (XX).

3. **Combining the Information**: When fertilization occurs, the sperm contributes either an X or a Y chromosome. If a sperm carrying an X chromosome fertilizes the egg (which always carries an X), the resulting embryo will be XX, which is female. If a sperm carrying a Y chromosome fertilizes the egg, the resulting embryo will be XY, which is male.

4. **Conclusion**: Both the assertion and the reason are correct. The assertion correctly identifies that the sex of the embryo is determined by the sperm's chromosome, and the reason correctly states that all eggs carry an X chromosome. Therefore, the assertion is supported by the reason.

5. **Final Answer**: The correct answer is that both the assertion and the reason are correct, and the reason explains the assertion.

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