Which physiological process is facilitated by the ribosome organelle?

Which of the following cell organelles lacks $DNA$ and a bounding membrane?

The ribosomes that occur exclusively in mammalian mitochondria are: (in $S$)

What is a polysome composed of?

Which critical ion concentration is required for the association of the two subunits of a ribosome?

Identify the relationship in the following analogy:
Eukaryotic ribosomes : $80S$ :: Prokaryotic ribosomes : ............ (in $S$)