percentage of `(G+C)` is

Options

A. `(G+C)/((A+G+T+C))xx100`
B. `(100)/(A+T)xxG+C`
C. `(G+C)/(A+T+G+C)`
D. `((G+C)xx(A+T))/(100)`

Answer

To solve the question regarding the percentage of (G + C) in a DNA sequence, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Components**:
- Nitrogenous bases in DNA are adenine (A), guanine (G), cytosine (C), and thymine (T).
- The question asks for the percentage of guanine (G) and cytosine (C) combined.

2. **Identify the Formula**:
- The formula for calculating the percentage of G + C is:
\[ \text{Percentage of } (G + C) = \frac{(G + C)}{(A + G + T + C)} \times 100 \]
- Here, \( (G + C) \) is the total amount of guanine and cytosine, and \( (A + G + T + C) \) is the total amount of all nitrogenous bases.

3. **Substitute Values**:
- If you have the values for G, C, A, and T, you can substitute them into the formula to calculate the percentage.

4. **Calculate the Percentage**:
- After substituting the values, perform the division and then multiply by 100 to get the percentage.

5. **Select the Correct Option**:
- Based on the derived formula, the correct option from the provided choices is:
\[ \text{Option: } \frac{G + C}{A + G + T + C} \times 100 \]

### Final Answer:
The percentage of (G + C) is given by the formula:
\[ \text{Percentage of } (G + C) = \frac{(G + C)}{(A + G + T + C)} \times 100 \]