Which one of the following is not given by Erwin Chargaff ?

Options

A. Base composition of DNA varies from one species to another
B. The base composition of DNA does not change with age, nutrition or changes in the environment
C. Molar amounts of adenine are equal to the molar amounts of thymine
D. DNA can transcribe RNA

Answer

To determine which statement was not given by Erwin Chargaff, we will analyze each of the provided options based on Chargaff's rules.

### Step-by-Step Solution:

1. **Understanding Chargaff's Rules**:
Erwin Chargaff is known for formulating rules regarding the composition of DNA, which were established in the early 1950s. Chargaff's rules primarily focus on the relationships between the four nucleotide bases in DNA.

2. **Analyzing Option 1**:
- **Statement**: "Base composition of DNA varies from one species to another."
- **Analysis**: This statement is true. Chargaff noted that different species have different base compositions in their DNA. For example, humans have a different number of base pairs compared to E. coli.
- **Conclusion**: This statement is consistent with Chargaff's findings.

3. **Analyzing Option 2**:
- **Statement**: "The base composition of DNA does not change with age, nutrition, changes in the environment."
- **Analysis**: This statement is also true. Chargaff's observations indicated that the base composition of DNA is stable and does not change significantly throughout the life of an organism.
- **Conclusion**: This statement aligns with Chargaff's rules.

4. **Analyzing Option 3**:
- **Statement**: "Molar amounts of adenine are equal to the molar amounts of thymine."
- **Analysis**: This statement is true and is one of Chargaff's key rules. He found that in DNA, the amount of adenine (A) always equals the amount of thymine (T) due to their complementary pairing.
- **Conclusion**: This statement is consistent with Chargaff's findings.

5. **Analyzing Option 4**:
- **Statement**: "DNA can transcribe RNA."
- **Analysis**: This statement is not one of Chargaff's rules. While it is true that DNA can be transcribed into RNA, this concept is part of the central dogma of molecular biology, which was articulated by Francis Crick, not Chargaff.
- **Conclusion**: This statement does not belong to Chargaff's contributions.

### Final Answer:
The statement that is not given by Erwin Chargaff is: **"DNA can transcribe RNA."**

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