Question

Depending upon the absence of or presence of ___on the surface of the endoplasmic reticulum, they can be smooth endoplasmic reticulum or rough endoplasmic reticulum.

Answer 1

Endoplasmic reticulum:

1. Endoplasmic reticulum is a scattered network-like structure which is found in cytoplasm.
2. The surface of ER may be provided with ribosomes.
3. The presence of ribosomes on the surface of the endoplasmic reticulum is known as the rough endoplasmic reticulum.
4. If ribosomes are absent in the surface of endoplasmic reticulum, it is called smooth endoplasmic reticulum.

Final answer: Depending upon the absence of or presence of ribosomes on the surface of the endoplasmic reticulum, they can be smooth endoplasmic reticulum or rough endoplasmic reticulum.