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 find 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**:
- In DNA, there are two types of nitrogenous bases: purines and pyrimidines.
- Purines include adenine (A) and guanine (G).
- Pyrimidines include cytosine (C) and thymine (T).

2. **Apply Chargaff's Rule**:
- Chargaff's rule states that in any DNA molecule, the amount of adenine (A) is equal to the amount of thymine (T), and the amount of guanine (G) is equal to the amount of cytosine (C).
- Therefore, we can express this as:
- A = T
- G = C

3. **Combine the Bases**:
- From Chargaff's rule, we can combine the bases:
- A + G = T + C
- This means that the total number of purines (A + G) is equal to the total number of pyrimidines (C + T).

4. **Calculate the Ratio**:
- Since A + G = C + T, the ratio of A + G to C + T can be expressed as:
- Ratio (A + G) : (C + T) = 1 : 1

5. **Conclusion**:
- Therefore, the ratio of the number of A + G to the number of C + T in the DNA of E. coli is 1:1.

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