The ratio of number of `A+G` to the number of `C+T` in DNA of E. Coli species is

Options

A. 1.1
B. 0.93
C. 1.52
D. 1.8

Answer

To solve the problem of finding the ratio of the number of adenine (A) plus guanine (G) to the number of cytosine (C) plus thymine (T) in the DNA of E. coli, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Components of DNA:**
- DNA is composed of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T).

2. **Apply Chargaff's Rules:**
- According to Chargaff's rules, in double-stranded DNA, the amount of adenine is equal to thymine (A = T) and the amount of guanine is equal to cytosine (G = C).
- This implies that the total amount of purines (A + G) is equal to the total amount of pyrimidines (C + T).

3. **Calculate the Ratio:**
- Since A + G = C + T, we can express this relationship as:
\[ \text{Ratio of (A + G) to (C + T)} = \frac{A + G}{C + T} = 1 \]
- Therefore, the ratio of the number of adenine plus guanine to the number of cytosine plus thymine in E. coli DNA is 1:1.

4. **Select the Correct Option:**
- Based on the calculated ratio, the answer is option A, which represents the 1:1 ratio.

### Final Answer:
The ratio of the number of A + G to the number of C + T in the DNA of E. coli species is **1:1**.

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