Define polysome.

Explanation

**Step-by-Step Solution:**

1. **Definition of Polysome:**
A polysome, also known as a polyribosome, is a structure formed by multiple ribosomes attached to a single strand of messenger RNA (mRNA).

2. **Formation of Polysome:**
When several ribosomes attach to one mRNA molecule, they create a chain-like structure. This arrangement allows for the simultaneous translation of the mRNA into proteins.

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