Photoautotrophic bacteria have

Options

A. Chloroplasts
B. Grana
C. Viruses
D. Mycorrhiza.

Answer

To answer the question "Photoautotrophic bacteria have," we will evaluate each of the provided options step by step.

### Step 1: Understand the concept of photoautotrophic bacteria
Photoautotrophic bacteria are organisms that can produce their own food using light energy through the process of photosynthesis. They contain pigments that capture light energy.

**Hint:** Remember that photoautotrophic bacteria utilize light for energy and are capable of synthesizing their own food.

### Step 2: Evaluate the first option - Chloroplast
Chloroplasts are double membrane-bound organelles found in eukaryotic cells, particularly in plants and algae, where photosynthesis occurs. However, bacteria are prokaryotic organisms and do not possess membrane-bound organelles, including chloroplasts.

**Hint:** Consider the cellular structure of bacteria when evaluating if they can have organelles like chloroplasts.

### Step 3: Evaluate the second option - Grana
Grana are structures found within chloroplasts that consist of stacks of thylakoids, which contain chlorophyll. Since bacteria do not have chloroplasts, they also do not have grana. However, some photoautotrophic bacteria, like cyanobacteria, have thylakoid membranes where photosynthesis occurs, but they do not have true grana as seen in eukaryotic cells.

**Hint:** Think about the differences between prokaryotic and eukaryotic structures when considering grana.

### Step 4: Evaluate the third option - Viruses
Viruses are not classified as living organisms and do not perform photosynthesis. They lack cellular structures and cannot be considered in the context of photoautotrophic bacteria.

**Hint:** Reflect on the characteristics of viruses and how they differ from bacteria.

### Step 5: Evaluate the fourth option - Mycorrhizae
Mycorrhizae are symbiotic associations between fungi and the roots of higher plants. This relationship is not applicable to bacteria, which do not form such associations.

**Hint:** Consider the nature of symbiotic relationships and whether bacteria can engage in them.

### Conclusion
After evaluating all options, we find that:
1. Chloroplasts are absent in prokaryotic organisms like bacteria.
2. Grana are associated with chloroplasts, which bacteria do not possess.
3. Viruses do not relate to bacteria in terms of photosynthesis.
4. Mycorrhizae are not applicable to bacteria.

Thus, the correct answer to the question "Photoautotrophic bacteria have" is that they have thylakoid membranes (not grana) where photosynthesis occurs, but since grana is the closest option, we can conclude that the correct answer is **Grana**.

**Final Answer:** Photoautotrophic bacteria have Grana (though they are more accurately described as having thylakoid membranes).