Question

when dr. montero was observing the endoplasmic reticulum of a cell using an electron microscope, she noticed that it was covered with ribosomes. what structure was she observing? smooth endoplasmic reticulum rough endoplasmic reticulum porous endoplasmic reticulum convoluted endoplasmic reticulum

Explanation:

Rough endoplasmic reticulum has ribosomes attached to its surface.

Answer:

C. rough endoplasmic reticulum