Centrioles Sites for active RNA synthesis.
Lysosomes Optimally active at a pH of about 8.5.
Thylakoids Flattened membranous sacs forming the grana of chloroplasts.
Ribosomes Those on chloroplasts are larger (80S) while those in the cytoplasm are smaller (70S).
C. Thylakoids Flattened membranous sacs forming the grana of chloroplasts.