Following are the stages in the cellular synthesis of a protein.
I. Movement of mRNA from the nucleus to cytoplasm.
II. Linking of adjacent amino acid molecules.
III. Transcription of mRNA from a DNA template.
IV. Formation of the polypeptide chain.
V. Attachment of the mRNA strand to a ribosome.
In which order do these stages take place?

Options

A. III I V II IV
B. I III II V IV
C. I V III IV II
D. III IV I II V

Answer

To determine the correct order of the stages in the cellular synthesis of a protein, we need to analyze the given statements step by step:

1. **Transcription of mRNA from a DNA template (Statement III)**: The first step in protein synthesis is transcription, where the DNA sequence is transcribed to form mRNA. This process occurs in the nucleus.

2. **Movement of mRNA from the nucleus to cytoplasm (Statement I)**: After transcription, the newly formed mRNA molecule exits the nucleus and moves into the cytoplasm, where it will be translated into a protein.

3. **Attachment of the mRNA strand to a ribosome (Statement V)**: Once in the cytoplasm, the mRNA strand attaches to a ribosome, which is the site of protein synthesis.

4. **Linking of adjacent amino acid molecules (Statement II)**: The ribosome reads the mRNA sequence and begins the process of translation, where tRNA molecules bring amino acids to the ribosome. These amino acids are linked together in the order specified by the mRNA.

5. **Formation of the polypeptide chain (Statement IV)**: As the amino acids are linked together, they form a polypeptide chain, which will eventually fold into a functional protein.

Putting these steps in order, we get:
- III (Transcription of mRNA from a DNA template)
- I (Movement of mRNA from the nucleus to cytoplasm)
- V (Attachment of the mRNA strand to a ribosome)
- II (Linking of adjacent amino acid molecules)
- IV (Formation of the polypeptide chain)

Thus, the correct order is: **III, I, V, II, IV**.