Which of the following feature is correct for cyanobacteria ?

Options

A. Presence of flagellum throughout the life cycle
B. Presence of chlorophyll a
C. Asexual reproduction is absent
D. Cannot perform nitrogen fixation

Answer

**Step-by-Step Solution:**

1. **Understanding Cyanobacteria:**
- Cyanobacteria are a group of photosynthetic bacteria that are often referred to as blue-green algae. They are known for their ability to perform photosynthesis and produce oxygen.

2. **Evaluating the Options:**
- **Option 1: Presence of flagellum throughout the life cycle.**
- This option is incorrect. Cyanobacteria do not have flagella throughout their life cycle. Some species may have flagella at certain stages, but it is not a defining feature of all cyanobacteria.

- **Option 2: Presence of chlorophyll A.**
- This option is correct. Cyanobacteria contain chlorophyll A, which is essential for photosynthesis. This pigment allows them to capture light energy and convert it into chemical energy.

- **Option 3: Asexual reproduction is absent.**
- This option is incorrect. Cyanobacteria can reproduce asexually through methods such as binary fission, fragmentation, or the formation of spores.

- **Option 4: Cannot perform nitrogen fixation.**
- This option is also incorrect. Many cyanobacteria have the ability to fix atmospheric nitrogen, converting it into a form that can be used by living organisms.

3. **Conclusion:**
- The correct feature of cyanobacteria from the given options is the presence of chlorophyll A.

**Final Answer:**
- The correct feature for cyanobacteria is the presence of chlorophyll A.

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