..... codons out of 64 codons, code for 20 amino acids.

Options

A. 61
B. 70
C. 64
D. 80

Explanation

To solve the question about how many of the 64 codons code for amino acids, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Codons**: Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids or signal the termination of protein synthesis.

2. **Total Codons**: There are a total of 64 possible codons that can be formed from the four nucleotides (A, U, C, G) in RNA.

3. **Codons for Amino Acids**: Out of these 64 codons, 61 codons are known to code for the 20 different amino acids.

4. **Stop Codons**: The remaining 3 codons do not code for any amino acids; instead, they are known as stop codons (or termination codons) which signal the end of protein synthesis.

5. **Conclusion**: Therefore, the number of codons that code for amino acids is 61.

### Final Answer:
The correct answer is **61** codons code for amino acids.

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