Question

Which of the following forms Nissl granules?
A) RER
B) SER
C) DNA
D) Golgi Bodies

Answer 1

Hint:Nissl granules are formed from endoplasmic reticulum having ribosomes. Nissl granules are also known as Nissl body or Nissl substance. It can give a slight color appearance to the cytoplasm of the cell body.

Complete answer:
Endoplasmic reticulum is a network of membrane-bound, branching and interconnecting tubules, vesicles and flattened sacs which is scattered in the cytoplasm. It contains enzymes, metabolites and synthetic products. Rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER) are the two types of endoplasmic reticulum. Nissl granules are formed from rough endoplasmic reticulum (RER). RER has attached ribosomes, whereas SER has no attached ribosomes. RER is the major location for the synthesis of secretory and export proteins. It is mainly concerned with the assembling, storage, processing and export of secretory proteins.

SER is mainly concerned with the synthesis of non-protein substances mainly lipids (glycerides, glycolipids, phospholipids, sterols etc.). It is also involved in the chemical modification of substances having low molecular weight, cellular detoxification mechanism and the formation of transport vesicles. It mostly occurs in cells, which actively engage in synthesis of lipids. So, it does not produce Nissl granules.

Figure: Rough endoplasmic reticulum (RER)

DNA and Golgi Bodies also do not produce Nissl granules. Therefore, the correct answer is Rough endoplasmic reticulum (RER).

Hence, the option is (A) correct.

Additional information:
Endoplasmic reticulum is present in almost all cells except prokaryotes and mature mammalian RBC.
It is poorly developed in egg cells, sperm cells and undifferentiated and rapidly dividing embryonic cells and cancer cells.
The 60s ribosomes are attached to Rough endoplasmic reticulum by means of protein ribophorin 1 and ribophorin 2.

Note: Endoplasmic reticulum exists in 3 morphologically different forms such as lamellae, vesicles and tubules. Lamellae are unbranched and flattened sac, arranged in parallel sacs. Vesicles are closed oval or rounded sacs. Tubules are branching and interconnecting units.