If the DNA condons are ATG ATG ATG and a cytosine base is inserted at the beginning , which of the following will result

Options

A. CAT GAT GATG
B. A non-sense mutation
C. C ATG ATG ATG
D. CA TGA TGA TG

Answer

To solve the question regarding the insertion of a cytosine base at the beginning of the DNA sequence "ATG ATG ATG," we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Original DNA Sequence:**
The original DNA sequence consists of three codons:
- Codon 1: ATG
- Codon 2: ATG
- Codon 3: ATG

2. **Insert the Cytosine Base:**
The question states that a cytosine (C) base is inserted at the beginning of the sequence. Thus, the new sequence becomes:
- New Sequence: C + ATG ATG ATG
- This results in: CATG ATG ATG

3. **Break Down the New Sequence into Codons:**
Codons are groups of three nucleotides. We will now break down the new sequence:
- Codon 1: CAT
- Codon 2: GAT
- Codon 3: GAT
- The last nucleotide (G) does not form a complete codon since it is alone.

4. **List the Resulting Codons:**
After the insertion and breakdown, the resulting codons are:
- First Codon: CAT
- Second Codon: GAT
- Third Codon: GAT
- Note: The last G is not part of a codon.

5. **Evaluate the Options:**
Now we compare the resulting codons with the provided options:
- Option 1: CAT, GAT, GAT, G (This matches our result)
- Option 2: Nonsense mutation (Not applicable here)
- Option 3: C alone (Incorrect as C is part of a codon)
- Option 4: Only two codons (Incorrect as we have three)

6. **Conclusion:**
The correct answer is Option 1: CAT, GAT, GAT, G.