Select an incorrect statement about algae?

Options

A. they reproduce by negatative, asexual and sexual methods
B. most common asexual spore is zoospores
C. Vegetative reproduction is by fragmentation
D. In Volvox sexual reproduction is isogamous

Answer

To solve the question of selecting an incorrect statement about algae, we will analyze each statement provided and determine which one is false.

### Step-by-Step Solution:

1. **Understanding Algae**:
- Algae are simple, chlorophyll-bearing organisms that are primarily aquatic and can perform photosynthesis. They can reproduce through various methods.

2. **Evaluating the Statements**:
- **Statement 1**: "They reproduce by vegetative, sexual, and asexual methods."
- This statement is correct. Algae can reproduce in all these ways.

- **Statement 2**: "The most common asexual spore is zoospores."
- This statement is also correct. Zoospores are indeed a common form of asexual reproduction in algae.

- **Statement 3**: "Vegetative reproduction is by fragmentation in wall bugs."
- This statement is correct. Fragmentation is a common method of vegetative reproduction in algae.

- **Statement 4**: "Sexual reproduction is isogamous."
- This statement is incorrect. While isogamous reproduction (fusion of similar-sized gametes) occurs in some algae, many, like Volvox, exhibit oogamous reproduction (fusion of a large non-motile female gamete and a small motile male gamete).

3. **Conclusion**:
- The incorrect statement about algae is **Statement 4**: "Sexual reproduction is isogamous."

### Final Answer:
The incorrect statement about algae is: **"Sexual reproduction is isogamous."**

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