Question

Many ribosomes may associate with a single $mRNA$ to form multiple copies of a polypeptide simultaneously. Such strings of ribosomes are termed as

• A. Nucleosome
• B. Polysome
• C. Plastidome
• D. Polyhedral bodies

Answer 1

The Correct Option is B

To understand the given question, we need to delve into the concept of ribosomes interacting with mRNA during the process of protein synthesis. When a single mRNA strand is translated, multiple ribosomes can attach to it, forming a complex known as a "polysome" or "polyribosome". Let's explore why this is the correct option and rule out the others:

1. Polysome: This is the correct answer. A polysome is a cluster of ribosomes bound to an mRNA molecule, allowing the simultaneous synthesis of multiple copies of a polypeptide. This is efficient for cells, as it speeds up protein production.
2. Nucleosome: This term refers to a segment of DNA wound around a core of histone proteins, which is involved in the structural organization of chromosomes. It is unrelated to mRNA translation or ribosomes.
3. Plastidome: This is not a commonly used term in molecular biology. It may be confused with plastids, which are components of plant cells involved in processes like photosynthesis, but they have no direct role in mRNA translation.
4. Polyhedral bodies: These are viral inclusion bodies found within certain infectious entities, like bacteria or other cells. They are unrelated to the process of translating mRNA with ribosomes.

Hence, the strings of ribosomes assembling on a single mRNA strand to synthesize multiple polypeptide copies are correctly termed "polysomes".