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.

nucleus

would be most reasonable answer tbh

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.