Which of the following is incorrect about Cyanobacteria?

Options

A. They are photoautotrophs
B. they lack heterocysts
C. they often form blooms in polluted water bodies
D. they have chlorophyll A aimilar to green plants

Answer

To determine which statement about Cyanobacteria is incorrect, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the Characteristics of Cyanobacteria**:
- Cyanobacteria are known to be photosynthetic organisms that can convert sunlight into energy. They are classified as photoautotrophs.

2. **Evaluate the First Option**:
- The first option states that "they are photoautotrophs". This is a true statement because cyanobacteria perform photosynthesis, using sunlight, carbon dioxide, and water to produce organic matter.

3. **Evaluate the Second Option**:
- The second option mentions "DELAC HETEROSYST". This seems to be a typographical error. The correct term is "heterocysts". Heterocysts are specialized cells found in some cyanobacteria that are responsible for nitrogen fixation. Therefore, if the statement implies that heterocysts are absent in cyanobacteria, it is incorrect.

4. **Evaluate the Third Option**:
- The third option states that "they often form blooms in polluted water bodies". This statement is correct, as cyanobacteria can proliferate rapidly in nutrient-rich (polluted) waters, leading to blooms.

5. **Evaluate the Fourth Option**:
- The fourth option states that "they have chlorophyll A similar to the green plants". This is also a true statement, as cyanobacteria contain chlorophyll A, which is the same pigment found in green plants.

6. **Conclusion**:
- After evaluating all options, the incorrect statement about cyanobacteria is the second option regarding "DELAC HETEROSYST" (which should refer to heterocysts).

### Final Answer:
The incorrect statement about Cyanobacteria is the second option regarding "DELAC HETEROSYST".