Butter Sandwich model of plasma membrane was proposed by

Options

A. Davson and Danielli
B. Robertson
C. Singer and Nicolson
D. Benson

Answer

To answer the question regarding who proposed the butter sandwich model of the plasma membrane, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Model**: The question asks about the "butter sandwich model" of the plasma membrane. This model describes the arrangement of lipids and proteins in the membrane.

2. **Research the Proposers**: The options provided are:
- Davison and Danielli
- Robertson
- Singer and Nicholson
- Benson

3. **Recall Historical Context**: The butter sandwich model is also known as the "lipid bilayer model," which suggests that the plasma membrane consists of a bilayer of lipids with proteins embedded in it.

4. **Link the Model to the Correct Scientists**: The butter sandwich model was proposed by scientists Davison and Danielli. They conducted studies on surface tension which led them to conclude that the lipid layer has low surface tension due to the adsorption of proteins.

5. **Eliminate Incorrect Options**:
- Robertson proposed the unit membrane model.
- Singer and Nicholson proposed the fluid mosaic model.
- Benson is not associated with any of these models.

6. **Conclude the Answer**: Based on the information gathered, the correct answer is Davison and Danielli.

### Final Answer:
The butter sandwich model of the plasma membrane was proposed by Davison and Danielli.

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