Correct option is B
The correct answer is (b).
Cycloheximide inhibits the 80S ribosome-associated eukaryotic cytosolic translation system. This drug specifically targets the elongation process in eukaryotic protein synthesis by preventing the movement of the ribosome along the mRNA. Cycloheximide does not affect prokaryotic ribosomes or those in mitochondria and chloroplasts (which are more similar to prokaryotic ribosomes, having a 70S structure).
Incorrect options-
Option (a) 70S bacterial ribosomes: Inhibited by antibiotics like chloramphenicol, tetracycline, and streptomycin, not by cycloheximide.
Option (c) 74S mitochondrial ribosomes: These are more bacterial-like and are not sensitive to cycloheximide but can be inhibited by chloramphenicol.
Option (d) 70S chloroplast ribosomes: Also similar to bacterial ribosomes and are resistant to cycloheximide; chloramphenicol affects these.
