Chargaff did not establish that

Options

A. `A:T = 1: 1`
B. `G: C = 1: 1`
C. `A+G:T+Cne1:1`
D. `A+T:G+Cne1:1`

Answer

**Step-by-Step Solution:**

1. **Understanding Chargaff's Rules**: Chargaff established two main rules regarding the base pairing in DNA. The first rule states that the amount of adenine (A) is equal to the amount of thymine (T), and the second rule states that the amount of guanine (G) is equal to the amount of cytosine (C). This can be summarized as:
- A = T
- G = C

2. **Analyzing the Third Rule**: Chargaff also mentioned a third relationship, which involves the total amounts of the bases. This rule states that the sum of adenine and thymine (A + T) is not necessarily equal to the sum of guanine and cytosine (G + C). This means:
- A + T ≠ G + C

3. **Identifying the Incorrect Statement**: The question asks what Chargaff did not establish. Based on the video transcript, it indicates that there is a misconception regarding the ratio of adenine plus guanine (A + G) to thymine plus cytosine (T + C). The incorrect assertion is that A + G = T + C, which is not a rule established by Chargaff.

4. **Conclusion**: Therefore, the statement that is incorrect and not established by Chargaff is that adenine plus guanine is equal to thymine plus cytosine (A + G = T + C).

**Final Answer**: Chargaff did not establish that adenine plus guanine is equal to thymine plus cytosine.

---