Assertion (A) :- An organism with lethal mutation may not even develop beyond the zygote stage.
Reason (R ) :- All types of gene mutations are lethal .

Options

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

Explanation

To solve the question, we need to evaluate both the assertion and the reason provided.

**Step 1: Analyze the Assertion (A)**
The assertion states: "An organism with lethal mutation may not even develop beyond the zygote stage."
- A lethal mutation is a genetic change that can cause the death of an organism. If such a mutation occurs in the zygote (the fertilized egg), it is likely that the organism will not survive to develop further. Therefore, this assertion is **true**.

**Step 2: Analyze the Reason (R)**
The reason states: "All types of gene mutations are lethal."
- This statement is incorrect. While some mutations can be lethal, many mutations are neutral or even beneficial. For example, some mutations can lead to variations that enhance survival or reproduction. Thus, not all gene mutations are lethal, making this reason **false**.

**Step 3: Conclusion**
Based on the analysis:
- The assertion is true (an organism with a lethal mutation may not develop beyond the zygote stage).
- The reason is false (not all gene mutations are lethal).

Thus, the correct answer is that the assertion is true, but the reason is false.

### Final Answer:
The assertion is true, but the reason is false.

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