I will give brainliest Protein synthesis can occur on the rough endoplasmic reticulum (ER) but not on the smooth ER. Which cell structures are attached to the surface of the rough ER that allow it to make proteins? Choose 1 (Choice A) A Ribosomes (Choice B) B Vacuoles (Choice C) C DNA strands (Choice D) D Chloroplasts

What makes the rough Endoplasmic reticulum rough are the ribosomes studded on it's surface. Answer is A ribosomes.

A. Ribosomes

Explanation:

Rough ER is called rough because it has ribosomes attached to its surface. The double membranes of smooth and rough ER form sacs called cisternae. Protein molecules are synthesized and collected in the cisternal space/lumen.

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