Question

which of the following best describes a difference between the rough er and the smooth er? choose 1 answer: a the smooth er is part of the endomembrane system, but the rough er is not. b the rough er produces lipids, but the smooth er does not. c the smooth er has ribosomes on its surface, but the rough er does not. d the rough er is a site of protein synthesis, but the smooth er is not.

Explanation:

The endoplasmic reticulum (ER) has two types: rough ER and smooth ER. Both are part of the endomembrane system. The rough ER has ribosomes attached to its surface and is a major site of protein synthesis. The smooth ER lacks ribosomes and is involved in lipid synthesis and other metabolic processes. Option A is incorrect as both are part of the endomembrane system. Option B is wrong because the smooth ER produces lipids, not the rough ER. Option C is incorrect since the rough ER has ribosomes, not the smooth ER.

Answer:

D. The rough ER is a site of protein synthesis, but the smooth ER is not.