Which is not found in RNA?

Options

A. Thymine
B. Uracil
C. Guanine
D. Cytosine

Answer

To determine which component is not found in RNA, we can follow these steps:

### Step 1: Understand the Composition of RNA
RNA, or ribonucleic acid, is a type of nucleic acid composed of nucleotides. Each nucleotide consists of three components: a ribose sugar, a phosphate group, and a nitrogenous base.

**Hint:** Recall the basic structure of nucleotides and their components.

### Step 2: Identify the Sugar in RNA
The sugar present in RNA is ribose, which is a five-carbon sugar. This distinguishes RNA from DNA, which contains deoxyribose.

**Hint:** Remember the difference between ribose and deoxyribose.

### Step 3: List the Nitrogen Bases in RNA
RNA contains four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and uracil (U). Notably, uracil replaces thymine, which is found in DNA.

**Hint:** Think about the base pairing rules and which bases are present in RNA versus DNA.

### Step 4: Identify the Missing Component
From the information gathered, we can conclude that thymine (T) is not found in RNA. Instead, uracil (U) is present in its place.

**Hint:** Compare the nitrogenous bases found in RNA and DNA to find the one that is missing in RNA.

### Step 5: Conclusion
Thus, the component that is not found in RNA is thymine.

**Final Answer:** Thymine is not found in RNA.