Identify the following point mutations in mRNA : UAU ACC UAU to UAU AAC CUA and UUG CUA AUA to UUG CUG AUA

Options

A. Transition and frame shift respectively
B. Transversion and frame shift respectively
C. Frame shift and transversion respectively
D. Frame shift and transition respectively

Explanation

To identify the point mutations in the given mRNA sequences, we will analyze each sequence step by step.

### Step-by-Step Solution:

1. **Identify the Original and Mutated Sequences:**
- Original Sequence 1: UAU ACC UAU
- Mutated Sequence 1: UAU AAC CUA
- Original Sequence 2: UUG CUA AUA
- Mutated Sequence 2: UUG CUG AUA

2. **Analyze the First Sequence:**
- Compare the original sequence (UAU ACC UAU) with the mutated sequence (UAU AAC CUA).
- The first codon (UAU) remains unchanged.
- The second codon changes from ACC to AAC.
- The third codon changes from UAU to CUA.

3. **Identify the Type of Mutation in the First Sequence:**
- The change from ACC to AAC indicates that one base (C) has been replaced with another (A), which results in a change in the amino acid sequence.
- The addition of an A in the second codon causes a shift in the reading frame for the subsequent codons.
- This type of mutation is known as a **frameshift mutation** because it alters the reading frame of the mRNA.

4. **Analyze the Second Sequence:**
- Compare the original sequence (UUG CUA AUA) with the mutated sequence (UUG CUG AUA).
- The first codon (UUG) remains unchanged.
- The second codon changes from CUA to CUG.
- The third codon (AUA) remains unchanged.

5. **Identify the Type of Mutation in the Second Sequence:**
- The change from CUA to CUG involves a substitution of one purine (A) with another purine (G).
- This type of mutation, where one purine is replaced by another purine, is known as a **transition mutation**.

6. **Summarize the Findings:**
- For the first sequence, the mutation is a **frameshift mutation**.
- For the second sequence, the mutation is a **transition mutation**.

### Final Answer:
- The point mutations identified are:
- First Sequence: **Frameshift Mutation**
- Second Sequence: **Transition Mutation**