Assertion: In each pregnancy there is always 50 per cent probability of either a male or a female child.
Reason: The genetic makeup of the sperm determines the sex of child.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are true but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is Flase.
D. If both Assertion & Reason are false.

Answer

To analyze the given assertion and reason, let's break down the problem step by step.

### Step 1: Understanding the Assertion
The assertion states that "In each pregnancy there is always 50 per cent probability of either a male or a female child."
- This is based on the fact that the sex of the child is determined by the combination of sex chromosomes contributed by both parents.

### Step 2: Understanding the Reason
The reason states that "The genetic makeup of the sperm determines the sex of the child."
- This is true because the male parent can contribute either an X or a Y chromosome through his sperm. The female parent always contributes an X chromosome.

### Step 3: Analyzing the Genetic Contribution
- Female (XX) contributes only X chromosomes.
- Male (XY) contributes either X or Y chromosomes.
- If the sperm carries an X chromosome, the resulting child will be XX (female).
- If the sperm carries a Y chromosome, the resulting child will be XY (male).

### Step 4: Probability Calculation
- Since there are two possibilities for the sperm (X or Y), the probability of having a male or female child is indeed 50% for each sex.

### Step 5: Conclusion
Both the assertion and the reason are true, and the reason correctly explains why the assertion is true.

### Final Answer
The correct option is A: both assertion and reason are true, and the reason is the correct explanation of the assertion.

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