Assertion: Euglena is an obligatory phototroph.
Reason: Euglena lacks nuclear membrane

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that "Euglena is an obligatory phototroph." This means that Euglena is a type of organism that requires light to produce its own food through photosynthesis.

2. **Understanding the Reason**: The reason given is that "Euglena lacks nuclear membrane." This statement is incorrect as Euglena is a eukaryotic organism, which means it does have a nuclear membrane.

3. **Analyzing Euglena's Characteristics**: Euglena is known to have chloroplasts, which allow it to perform photosynthesis when light is available. However, it can also absorb nutrients from its environment when light is not available, indicating that it is not strictly an obligatory phototroph.

4. **Conclusion on the Assertion and Reason**: Since the assertion claims that Euglena is an obligatory phototroph, which is not entirely true (as it can also be heterotrophic), and the reason provided is incorrect (Euglena does have a nuclear membrane), we can conclude that both the assertion and the reason are false.

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

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