The association of more than one ribosome with a single molecule of mRNA complex is known as

The correct option is Polysome.

During the process of translation in protein synthesis, multiple ribosomes can simultaneously bind to and translate a single messenger RNA (mRNA) molecule. This allows a cell to rapidly produce multiple copies of the same polypeptide chain from a single mRNA template.

This structure, consisting of a complex of an mRNA molecule and two or more ribosomes, is called a polysome (also known as a polyribosome).

Let us briefly look at why the other options are incorrect:
- Polypeptide: This refers to a continuous, unbranched chain of amino acids joined by peptide bonds, which forms a protein. It is a product of translation, not the mRNA-ribosome complex itself.
- Polymer: This is a broad chemical term for any large molecule made up of repeating structural units (monomers). While mRNA and proteins are polymers, this term is too general and does not describe the specific mRNA-ribosome complex.
- Polysaccharide: This is a carbohydrate consisting of long chains of monosaccharide units bound together, such as starch, glycogen, or cellulose. It is completely unrelated to the translation complex.