Prokaryotic ribosomes are particles about `200Å` units in diameter consisting of protein and RNA . The percentage of protein and RNA respectively is

Options

A. 60% and 40%
B. 40% and 60%
C. 80% and 20%
D. 50% and 50%

Answer

To determine the percentage of protein and RNA in prokaryotic ribosomes, we can follow these steps:

### Step 1: Understand the Composition of Prokaryotic Ribosomes
Prokaryotic ribosomes are made up of both proteins and ribosomal RNA (rRNA). The total structure is a combination of these two components.

### Step 2: Analyze the Given Options
We have four options to consider:
1. 60% protein and 40% RNA
2. 40% protein and 60% RNA
3. 80% protein and 20% RNA
4. 50% protein and 50% RNA

### Step 3: Recall the Known Composition
It is known from biological studies that prokaryotic ribosomes typically consist of approximately 60% rRNA and 40% protein. This is a key fact that we need to remember.

### Step 4: Evaluate Each Option
- **Option 1 (60% protein, 40% RNA)**: This is incorrect as it reverses the known percentages.
- **Option 2 (40% protein, 60% RNA)**: This matches the known composition of prokaryotic ribosomes, making it a potential correct answer.
- **Option 3 (80% protein, 20% RNA)**: This is incorrect as it does not reflect the known composition.
- **Option 4 (50% protein, 50% RNA)**: This is also incorrect as it does not match the known percentages.

### Step 5: Conclusion
Based on the analysis, the correct answer is **Option 2: 40% protein and 60% RNA**.

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