Which of these is not correct regarding ribosomes?
Present in the cytoplasm and on RER
Absent in chloroplast and mitochondria
Take part in protein synthesis
The correct option is C Absent in chloroplast and mitochondria
Ribosomes are naked ribonucleoprotein protoplasmic particles (RNP) which
function as a site for protein synthesis. Depending upon the location
of their occurrence, ribosomes are of two types, cytoplasmic and
organelle. The organelle ribosomes are found in plastids
(plasitdoribosomes) and mitochondria (mitoribosomes) which are $$70S$$
in nature. The cytoplasmic ribosomes (cytoribosomers) may remain free in
the cytoplasmic matrix or are attached to the cytosolic surface of
endoplasmic reticulum. So, the correct answer is 'Absent in chloroplast and mitochondria'.