Question

Who proposed the fluid mosaic model of plasma membrane?
A. Camillo golgi
B. Schledien and schwann
C. Singer and nicolson
D. Robert brown

Answer 1

Hint:Plasma membrane is the outermost membrane of the cell. It is also called selectively permeable membrane because it allows entry or exit of some selected substances in or out of the cell.

Complete answer:
Plasma membrane is semi-permeable in nature. The lipids and proteins form the boundaries. The membrane separates the contents of the cell from the extracellular fluid. The contents are cell organelles and cytoplasm. Some organisms have a cell wall along with plasma membrane. It is rigid in nature and gives shape to the cell. Example: fungi and plants.

Option A: Camillo golgi discovered golgi apparatus or golgi complex. It is a cell organelle present in eukaryotic organisms. It is made of flat discs arranged parallely above each other. It helps in packaging and processing proteins. Therefore, this is the incorrect option.

Option B: Schledien and schwann presented the cell theory. It describes that cell is the basic fundamental unit of life and all cells arise from preexisting cells. Therefore, this is the incorrect option.

Option C: Singer and Nicolson gave a fluid mosaic model of plasma membrane. According to the model, there is a bilpid layer of phospholipids. The proteins embedded in it are called integral proteins and there are certain membrane receptors and peripheral proteins. Therefore, this is the correct option.

Option D: Robert Brown discovered nucleus in 1831 and not a fluid mosaic model. Therefore, this is the incorrect option.

Hence the correct answer is option ‘C’ i.e, Singer and nicolson

Note:Peripheral proteins can be easily removed but integral proteins cannot be removed. The fluid mosaic model includes phospholipids, cholesterol, lipids, proteins and carbohydrates. Lipids and proteins are mobile within the membrane. Non-covalent interactions between phospholipids lend strength to the membrane.