Question

Ribosomes of the cytoplasm, chloroplast and mitochondrion are respectively?

• A. $80S,80S$, and $70S$
• B. $80S,70S$, and $70S$
• C. $70S$ in all
• D. $80S$ in all

Answer 1

The correct option is B $80S,70S$, and $70S$

Ribosomes are the granular structures composed of RNA and proteins. The eukaryotic ribosomes are 80S while the prokaryotic ribosomes are 70S . The cytoplasmic ribosomes are 80S whereas the ribosomes of chloroplast are smaller i.e.; 70S. Mitochondria is a prokaryotic one containing 70S ribosomes. The 'S' is a Svedberg unit stands for the sedimentation coefficient . It indirectly measures the density and size.

So, the correct option is 'Option B' .