Question

Which of the following statements is/are not true about endoplasmic reticulum (ER)?

• A. Cisterns
• B. Endoplasmic reticulum is of two types: smooth and rough.
• C. RER is involved in protein synthesis.
• D. SER does not have ribosomes attached to it.

Answer 1

The correct option is option (D):

Explanation for the correct option:

1. Endoplasmic reticulum is a network of tubular structures present in the cytoplasm.
2. It is located near the nucleus.
3. Degradation of cellular material is not a function of endoplasmic reticulum.
4. Degradation of cellular wastes and materials is carried out by lysosomes.
5. Hence statement D is incorrect.

Explanation for incorrect options:

Option (A):

The ER which has ribosomes attached to its surface is called RER. Due to the presence of ribosomes RER is involved in protein synthesis.

Option (B):

SER or smooth endoplasmic reticulum are those ER which are devoid of ribosomes on their surface.

Option (C):

There are two types of ER namely RER (ER which has ribosomes on its surface) and SER (ER which lacks ribosomes on its surface).

Final answer: Statement D is incorrect.