Branched chain lipids occur in the cell membranes of

Options

A. Acetinomycetes
B. Spirochaetes
C. Eubacteria
D. Archaebacteria.

Answer

To solve the question "Branched chain lipids occur in the cell membranes of," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking about the occurrence of branched chain lipids in the cell membranes of specific organisms. We need to identify which of the given options contains these lipids.

2. **Analyze the Options**: The options provided are:
- Acetonomycetes
- Spirochetes
- Eubacteria
- Archaebacteria

3. **Research Characteristics of Each Option**:
- **Acetonomycetes**: These are a type of bacteria that do not typically have branched chain lipids in their membranes.
- **Spirochetes**: These are a group of bacteria known for their spiral shape, but they do not primarily have branched chain lipids.
- **Eubacteria**: This is a broad category of bacteria that generally have straight-chain fatty acids in their membranes.
- **Archaebacteria**: These are a distinct group of prokaryotes that often live in extreme environments. They are known to have unique membrane lipids that include branched chain lipids.

4. **Identify the Correct Answer**: Based on the characteristics of the organisms, we find that branched chain lipids are specifically found in the cell membranes of Archaebacteria.

5. **Conclusion**: Therefore, the correct answer to the question is **Archaebacteria** (Option 4).

### Final Answer:
Branched chain lipids occur in the cell membranes of **Archaebacteria**.

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