The minimum requirement for mutation is :-

Options

A. change of triplet codon
B. Change in single nucleotide
C. Change in whole DNA
D. Change in single strand of DNA

Answer

To determine the minimum requirement for a mutation, we need to analyze the options provided and understand the basic concepts of genetics and mutations.

### Step-by-Step Solution:

1. **Understanding Mutation**:
- A mutation refers to a change in the DNA sequence that can lead to changes in the structure and function of proteins.

2. **Identifying the Options**:
- The options given are:
- A) Change of triplet codon
- B) Change in single nucleotide
- C) Change in whole DNA
- D) Change in single strand of DNA

3. **Analyzing Each Option**:
- **A) Change of triplet codon**: A triplet codon consists of three nucleotides. While a change in a triplet codon can lead to a mutation, it is not the minimum requirement since it involves multiple nucleotides.
- **B) Change in single nucleotide**: A single nucleotide change (also known as a point mutation) is the smallest possible mutation that can occur. This is the minimum requirement for a mutation.
- **C) Change in whole DNA**: This implies a change in the entire DNA sequence, which is not necessary for a mutation to occur.
- **D) Change in single strand of DNA**: This does not specify a mutation in terms of sequence change; it could refer to structural changes rather than sequence changes.

4. **Conclusion**:
- The minimum requirement for a mutation is a change in a single nucleotide, as this represents the smallest unit of genetic change.

### Final Answer:
The correct option is **B) Change in single nucleotide**.