Where are ribosomes synthesized?

In which organelle is $rRNA$ found?

Which of the following organelles is found in both prokaryotic and eukaryotic cells?

Besides the nucleus,eukaryotic cells have other membrane-bound distinct structures called organelles. Which one is odd according to the given statement?

Which one of the following elements is an important binding agent in ribosomes during protein synthesis?

What does '$S$' refer to in a $70S$ and an $80S$ ribosome?