AP BIOLOGY

Detailed explanation-1: -It is estimated, however, that the chloroplast contains between 2000 and 5000 different proteins; thus, the majority of chloroplast proteins are encoded by the nuclear genome.

Detailed explanation-2: -In chloroplasts, a few thousand proteins function in photosynthesis, expression of the chloroplast genome, and other processes. Most chloroplast proteins are synthesized in the cytoplasm, imported, and then targeted to a specific chloroplast compartment.

Detailed explanation-3: -The protein biosynthesis in chloroplasts is catalysed by a bacterial‐type 70S ribosome (Tiller & Bock, 2014), called chloroplast ribosome, composed of a 50S large subunit and a 30S small subunit.

Detailed explanation-4: -Consistent with their postulated origin from endosymbiotic cyanobacteria, chloroplasts of plants and algae have ribosomes whose component RNAs and proteins are strikingly similar to those of eubacteria.