Which of the following is a false statement ?

Options

A. Only heterotrophic and not photosynthetic protists are flagellated
B. Among the protists, only green algae have a sexual life cycle
C. Ciliates exchange genetic material during conjugation
D. Slime moulds have an amoeboid stage

Explanation

To determine which statement is false, we need to analyze each of the given statements about protists carefully.

### Step-by-Step Solution:

1. **Evaluate the First Statement**:
- The statement claims that "only heterotrophic and non-photosynthetic protists are flagellated."
- This statement is false because there are photosynthetic protists that are also flagellated, such as euglenoids, diatoms, and dinoflagellates. These organisms possess chloroplasts and can synthesize their own food.

2. **Evaluate the Second Statement**:
- The statement claims that "among the protists, only green algae have a sexual life cycle."
- This statement is true. Green algae do have a sexual life cycle where they produce male and female gametes that combine to form a zygote.

3. **Evaluate the Third Statement**:
- The statement claims that "ciliates exchange genetic material during conjugation."
- This statement is also true. Ciliates do exchange genetic material during the process of conjugation, which is a form of genetic recombination.

4. **Evaluate the Fourth Statement**:
- The statement claims that "slime molds have an amoeboid stage."
- This statement is true. Slime molds do have an amoeboid stage in their life cycle.

5. **Conclusion**:
- After evaluating all statements, we find that the first statement is the only false statement. Therefore, the answer to the question is that the first statement is false.

### Final Answer:
The false statement is: "Only heterotrophic and non-photosynthetic protists are flagellated."

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