Change from purine to pyrimidine or pyrimidine to purine is called :

Options

A. translation
B. transcription
C. transition
D. mangeisum sulphate

Answer

To answer the question regarding the change from purine to pyrimidine or pyrimidine to purine, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Nucleotide Bases**:
- Nucleotide bases are categorized into two groups: purines and pyrimidines.
- Purines have a double-ring structure and include adenine (A) and guanine (G).
- Pyrimidines have a single-ring structure and include cytosine (C), thymine (T), and uracil (U).

2. **Identifying the Type of Change**:
- The question asks about the change from purine to pyrimidine or vice versa.
- This change involves the substitution of one type of base for another.

3. **Defining the Terms**:
- The term for the change from purine to pyrimidine or from pyrimidine to purine is called a **transition**.
- This is specifically when a purine is replaced by another purine or a pyrimidine is replaced by another pyrimidine.

4. **Clarifying Related Terms**:
- If a purine is replaced by another purine or a pyrimidine is replaced by another pyrimidine, this is referred to as a **transversion**.
- Thus, the change from purine to pyrimidine or pyrimidine to purine is distinctly termed as a **transition**.

5. **Conclusion**:
- Therefore, the answer to the question is that the change from purine to pyrimidine or pyrimidine to purine is called a **transition**.