Q. Which one of the following cellular parts is correctly described ?
A) Thylakoids – flattened membranous sacs forming the grana of chloroplasts
B) Centrioles – sites for active RNA synthesis
C) Ribosomes – those on chloroplasts are larger (80S) while those in the cytoplasm are smaller (70S)
D) Lysosomes – optimally active at a pH of about 8.5
Explanation
[Solution from source] Thylakoids are flattened membranous sacs stacked into grana inside chloroplasts. Chloroplast ribosomes are the smaller 70S type and cytoplasmic ones are 80S, lysosomes work best at an acidic pH of about 5, and centrioles organise spindles rather than making RNA. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.