Many ribosomes may associate with a single mRNA to form mutiple copies of a poolypeptide simultaneously. Such strings of ribosomes are termed as

Options

A. Nucleosome
B. Platidome
C. Polyhedral bodies
D. Polysome

Answer

### Step-by-Step Solution:

1. **Understanding Ribosomes and mRNA**:
- Ribosomes are cellular structures that synthesize proteins by translating messenger RNA (mRNA) into polypeptides. They consist of two subunits (large and small) that come together during protein synthesis.

2. **Role of mRNA in Protein Synthesis**:
- mRNA carries the genetic information from DNA to the ribosomes, where it serves as a template for assembling amino acids into a polypeptide chain.

3. **Multiple Ribosomes on a Single mRNA**:
- It is common for multiple ribosomes to attach to a single mRNA strand. This allows for the simultaneous synthesis of multiple copies of a polypeptide, increasing the efficiency of protein production.

4. **Formation of Polysomes**:
- When several ribosomes are attached to one mRNA strand, they form a structure known as a polysome (or polyribosome). Each ribosome in the polysome translates the mRNA into a polypeptide, resulting in the production of multiple polypeptides from one mRNA molecule.

5. **Identifying the Correct Term**:
- Given the options: nucleosome, plastidome, polyhedral bodies, and polysome, the correct term for the structure formed by multiple ribosomes translating a single mRNA is "polysome."

### Final Answer:
The strings of ribosomes that associate with a single mRNA to form multiple copies of a polypeptide simultaneously are termed **polysomes**.

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