Question

why the RERappers rough

Answer 1

hello friend...

Rough Endoplasmic Reticulum appears rough because on it's surface Ribosomes present. These ribosomes are small granule like so it makes ER rough.

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Answer 2

"This is an extensive organelle composed of greatly convoluted but flattish sealed sacs, which are contiguous with the nuclear membrane. It is called 'rough' endoplasmic reticulum because it is studded on its outer surface (the surface in contact with the cytosol) with ribosomes."