After transcription , which of the following is added to the 3' end of the eukaryotic mRNA ?

Options

A. Introns
B. Cap of modified Guanine nucleotide
C. Poly A tail
D. Trinucleotide CCA

Answer

To solve the question "After transcription, which of the following is added to the 3' end of the eukaryotic mRNA?", we can follow these steps:

### Step 1: Understand the context of the question
After transcription, eukaryotic mRNA undergoes several modifications before it is translated into protein. One of these modifications involves the addition of specific nucleotides at the ends of the mRNA.

**Hint:** Remember that eukaryotic mRNA is processed after transcription, and this includes modifications at both the 5' and 3' ends.

### Step 2: Analyze the options provided
1. **Introns**: These are non-coding regions of the RNA that are removed during RNA splicing. Therefore, they are not added to the mRNA.

**Hint:** Introns are removed, not added, during mRNA processing.

2. **Cap of Modified Guanine Nucleotide**: This is actually added to the 5' end of the mRNA, not the 3' end. So this option is incorrect.

**Hint:** The 5' cap is crucial for mRNA stability and initiation of translation.

3. **Poly-A tail**: This is a sequence of adenine nucleotides added to the 3' end of the mRNA. This modification is important for mRNA stability and export from the nucleus.

**Hint:** The Poly-A tail protects mRNA from degradation and aids in the translation process.

4. **Trinucleotide CCA**: This sequence is associated with tRNA, not mRNA. It is not added to the 3' end of mRNA.

**Hint:** CCA is specific to tRNA and is not a modification of mRNA.

### Step 3: Identify the correct answer
Based on the analysis of the options, the correct answer is the **Poly-A tail**, which is added to the 3' end of the eukaryotic mRNA after transcription.

**Final Answer:** The correct answer is the Poly-A tail.