Who proposed the trilaminar or 3-layered structure of cell membrane ?

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the scientist who proposed the trilaminar or three-layered structure of the cell membrane.

2. **Identifying Key Terms**: The key terms in the question are "trilaminar" and "three-layered structure" of the cell membrane. This refers to the model that describes the arrangement of lipids and proteins in the cell membrane.

3. **Recalling Relevant Information**: The trilaminar model of the cell membrane is significant in cell biology. It describes how the cell membrane is composed of a lipid bilayer with proteins embedded within it.

4. **Finding the Scientist**: The scientist who is credited with proposing this model is J.D. Robertson. He introduced the concept of the trilaminar structure based on his observations.

5. **Final Answer**: Therefore, the answer to the question is J.D. Robertson.

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