What is the ratio of non sense codons to sense codons respectively?

Options

A. `61:3`
B. `3:61`
C. `1:20`
D. `20:1`

Answer

To find the ratio of non-sense codons to sense codons, we can follow these steps:

### Step 1: Understand the Definitions
- **Non-sense codons**: These are codons that do not code for any amino acids and signal the termination of translation. There are three known non-sense codons.
- **Sense codons**: These are codons that code for amino acids.

### Step 2: Identify the Number of Non-sense Codons
- There are a total of **3 non-sense codons**. These are:
- UAG (Amber)
- UAA (Ochre)
- UGA (Opal)

### Step 3: Identify the Total Number of Codons
- The genetic code consists of **64 codons** in total (4 nucleotides in groups of 3).

### Step 4: Calculate the Number of Sense Codons
- Out of the 64 codons, 3 are non-sense codons. Therefore, the number of sense codons is:
- 64 total codons - 3 non-sense codons = **61 sense codons**.

### Step 5: Formulate the Ratio
- Now, we can form the ratio of non-sense codons to sense codons:
- Non-sense codons (3) : Sense codons (61) = **3 : 61**.

### Conclusion
- The ratio of non-sense codons to sense codons is **3:61**. Therefore, the correct answer is option B.

---