Solution

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'.