Assertion: In gel electrophoresis, DNA fragments are separated.
Reason: DNA is negatively charged, so it moves towards anode under electric field.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Gel Electrophoresis**: Gel electrophoresis is a laboratory technique used to separate DNA fragments based on their size. It is commonly used in DNA fingerprinting and various molecular biology applications.

2. **Assertion Explanation**: The assertion states that "In gel electrophoresis, DNA fragments are separated." This is true as the primary purpose of gel electrophoresis is to separate DNA fragments for analysis.

3. **Reason Explanation**: The reason states that "DNA is negatively charged, so it moves towards anode under electric field." This is also true. DNA molecules carry a negative charge due to their phosphate backbone, which causes them to migrate towards the positively charged anode when an electric field is applied during electrophoresis.

4. **Mechanism of Separation**: When the DNA fragments are loaded into wells in an agarose gel and an electric current is applied, the negatively charged DNA moves towards the anode. The gel matrix acts as a sieve, allowing smaller fragments to move faster than larger ones, thus separating them based on size.

5. **Conclusion**: Both the assertion and reason are correct. Furthermore, the reason provided is a correct explanation for the assertion. Therefore, the correct conclusion is that both A (assertion) and R (reason) are true, and R is the correct explanation of A.

**Final Answer**: Both A and R are true, and R is the correct explanation of A.

---