Which statement is not correct :-

Options

A. DNA and RNA are able to mutate
B. RNA being unstable, mutate at a faster rate compare to DNA
C. The presence of thymine at the place of uracil also confers
additional stability to DNA
D. DNA is not dependent on RNA for synthesis of protein

Answer

To determine which statement is not correct among the given options, we will analyze each statement step by step.

### Step 1: Analyze the First Statement
**Statement:** DNA and RNA are able to mutate.
**Analysis:** This statement is correct. Both DNA and RNA can undergo mutations, leading to variations in genetic material.

**Hint:** Consider the role of mutations in genetic diversity.

### Step 2: Analyze the Second Statement
**Statement:** RNA being unstable mutates at a faster rate compared to DNA.
**Analysis:** This statement is also correct. RNA is generally more unstable than DNA due to its ribose sugar and the presence of uracil instead of thymine, which contributes to its higher mutation rate.

**Hint:** Think about the structural differences between RNA and DNA that affect stability.

### Step 3: Analyze the Third Statement
**Statement:** The presence of thymine in place of uracil confers additional stability to DNA.
**Analysis:** This statement is correct as well. The presence of thymine in DNA provides more stability compared to uracil in RNA, which is one reason DNA is more stable than RNA.

**Hint:** Reflect on the nitrogenous bases and their roles in stability.

### Step 4: Analyze the Fourth Statement
**Statement:** DNA is not dependent on RNA for synthesis of proteins.
**Analysis:** This statement is incorrect. According to the central dogma of molecular biology, DNA is transcribed into RNA, which is then translated into proteins. Therefore, DNA does depend on RNA for protein synthesis.

**Hint:** Recall the central dogma of molecular biology and the flow of genetic information.

### Conclusion
The statement that is not correct is: **"DNA is not dependent on RNA for synthesis of proteins."** Therefore, the answer is **D**.