Within the cell, ribosomes are found in
a)	Cytoplasm
b)	Chloroplasts (in plants) and mitochondria
c)	Rough ER
d)	All of the above

(d)

In eukaryotes, ribosomes are found in chloroplasts and mitochondria. In prokaryotes, ribosomes occur freely in the cytoplasmic matrix

In eukaryotic cells, RER possesses ribosomes attached to its membranes

Ribosomes occur in all living cells with the exception of mammalian erythrocytes or red blood corpuscles