Why does the Rough Endoplasmic Reticulum look 'rough' under a microscope?
A.Due to the presence of ribosomes on its surface✓ Correct
B.Due to the absence of ribosomes on its surface
C.Due to the presence of lysosomes on its surface
D.Due to the presence of mitochondria on its surface
Explanation
The Rough Endoplasmic Reticulum (RER) appears 'rough' under the microscope due to the presence of ribosomes attached to its outer surface (cytoplasmic side). These ribosomes give it a granular or studded appearance. The ribosomes attached to RER are involved in the synthesis of proteins, particularly those destined for secretion, membrane insertion, or transport to other organelles. In contrast, the Smooth Endoplasmic Reticulum (SER) lacks ribosomes and appears smooth; it is involved in lipid synthesis, detoxification, and calcium storage. Lysosomes and mitochondria are separate organelles and are not present on the ER surface.
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