Assertion: Grasshopper is an example of XO type of sex determination in which the males have only one X-chromosome besides the autosomes, whereas females have a pair of X-chromosomes.
Reason: In a number of insects and mammals including man XY types of sex determination is seem where both male and female have same number of chromosome.

Options

A. Assertion and reason both are correct statements and reason is the correct explanation of the assertion.
B. Assertion and reason both are correct statements, but reason is not the correct explanation of the assertion.
C. Assertion is true, but reason is false statement.
D. Assertion is false, but reason is true statement.

Answer

To analyze the given assertion and reason, we will break down the statements and evaluate their correctness step by step.

### Step 1: Evaluate the Assertion
**Assertion:** Grasshopper is an example of XO type of sex determination in which the males have only one X-chromosome besides the autosomes, whereas females have a pair of X-chromosomes.

- In grasshoppers, the males have one X chromosome (X0), while females have two X chromosomes (XX). This is indeed a characteristic of the XO type of sex determination. Therefore, the assertion is **true**.

### Step 2: Evaluate the Reason
**Reason:** In a number of insects and mammals including man, XY types of sex determination is seen where both male and female have the same number of chromosomes.

- In XY type of sex determination, males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). In humans and many other mammals, the total number of chromosomes is indeed the same for both sexes (46 chromosomes, or 23 pairs). Therefore, the reason is also **true**.

### Step 3: Analyze the Relationship Between Assertion and Reason
- Both the assertion and the reason are correct statements. However, the reason provided does not explain the assertion. The assertion specifically discusses the XO type of sex determination in grasshoppers, while the reason discusses the XY type in humans and other mammals. Thus, while both statements are true, the reason is not a proper explanation for the assertion.

### Conclusion
- The correct answer is that both the assertion and reason are true, but the reason is not the correct explanation for the assertion.

### Final Answer
Both statements are true, but the reason is not the correct explanation for the assertion.

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