Which of the following biomolecules is not present in ribosomes?

To determine which biomolecule is not present in ribosomes, we need to understand the composition of ribosomes and the biomolecules typically found in them.

Ribosomes are composed of two subunits, known as the large subunit and the small subunit. These subunits are made up of various biomolecules, including ribosomal RNA (rRNA) and proteins.

The rRNA molecules are responsible for the structural integrity and catalytic activity of ribosomes. They play a crucial role in the translation of genetic information from messenger RNA (mRNA) into proteins. Therefore, rRNA is definitely present in ribosomes.

Proteins, on the other hand, are also an essential component of ribosomes. They help in stabilizing the structure of ribosomes and facilitating the binding of mRNA and transfer RNA (tRNA) during protein synthesis.

Based on this information, we can conclude that both rRNA and proteins are present in ribosomes. Therefore, the biomolecule that is not present in ribosomes is deoxyribonucleic acid (DNA). DNA is the genetic material that carries the instructions for the synthesis of proteins, but it is not a direct component of ribosomes.