The main function of the rough endoplasmic reticulum is the production of Q 1. mitochondria and proteins secreted by the cell.

2. hydrogen peroxide and steroid hormones secreted by the cell.

3. ribosomes and steroid hormones.

4. membrane and proteins secreted by the cell.

The main function of the RER is the production of membrane and secretory proteins. Option D is correct.

Rough endoplasmic reticulum (RER) :

It is a membranous organelle that is a part endo-membrane system in the cell.

Therefore, the main function of the RER is the production of membrane and secretory proteins.

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4. Membrane and proteins secreted by the cell

Explanation:

Endoplasmic reticulum (ER) is one of the organelle that makes up the endomembrane system of eukaryotes. The ER is of two types viz: rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER).

The RER is called "rough" because of the ribosome organelles that are attached to its surface. The attachment of this ribosomes (site of protein synthesis) also defines its function. The RER is principally involved in the production of protein. Hence, the Rough Endoplasmic Reticulum functions mainly in the production of membrane and proteins secreted by the cell.