Which organelle is found in the endoplasmic reticulum,mitochondria,and chloroplasts?

Protein synthesis in an animal cell occurs

What are the subunits of ribosomes in a eukaryotic cell?

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

An element which helps in joining the subunits of ribosomes is

Which cell organelle is described by the following statements?
$(A)$ Granular structure.
$(B)$ First observed under an electron microscope as dense particles by $George\, Palade$.
$(C)$ Composed of $RNA$ and proteins.
$(D)$ Not surrounded by any membrane.