Plasma Membrane MCQs

The plasma membrane is a biological membrane that surrounds all live cells and serves to separate internal and external components. It protects the cell from a variety of external stresses and chemicals. The phospholipid bilayer is made up of proteins, lipids, carbohydrates, and other substances. The plasma membrane’s different components make it a selectively permeable barrier.

It is “semi-permeable” because cellular transport mechanisms control what goes in and out of it, it is semi-permeable. It is incredibly flexible, enabling some cells to alter form as they move through tight capillaries, such as red blood cells and white blood cells. Because the cell includes protoplasm (or simply plasm), which is a semi-fluid living substance, it is termed a plasma membrane. The plasm, or living matter, is contained inside the plasma membrane, a biological membrane. This plasma membrane is referred to as the cell membrane since it covers the whole cell.

1. The transfusion diffusion movement of ____________ 

a) cholesterol molecule 

b) amino acid 

c) protein 

d) phospholipid 

Answer: (d)

Explanation: There are two forms of membrane phospholipid movements: lateral shift, which is movement from one point in the bilayer membrane to another inside the same leaflet; and transverse diffusion, which is movement from one side of the membrane to the other and is a somewhat protracted process.

2. The physical condition of the _____________ 

a) amino acids 

b) external phospholipids 

c) membrane phospholipids 

d) membrane appendages 

Answer: (c)

Explanation: Because integral proteins are incorporated in the membrane’s phospholipid bilayer, their mobility is substantially regulated by the physical state of membrane phospholipids.

3. Two cells may be controlled in such a manner that their plasma membranes become one and the same.

a) True 

b) False 

Answer: (a)

Explanation: Two cells from different species may be merged to create a common cytoplasm and a single continuous membrane using a procedure known as cell fusion.

4. Which of the following cannot be utilised to induce the fusing of two distinct cell plasma membranes?

a) electric shock 

b) inactivated viruses 

c) Polyethylene glycol 

d) emulsifier 

Answer: (d)

Explanation: There are a variety of strategies that may be utilised to fuse two distinct cells, but they all rely on modifying or attaching to the plasma membrane’s surface (inactivated viruses). Emulsifiers, on the other hand, perform neither and so aren’t employed in cell fusion. 

5. The FRAP method may be used to examine live cells.

a) True 

b) False 

Answer: (a)

Explanation: FRAP is a method that uses a light microscope to track the passage of molecules across a live cell’s plasma membranes.

6. The erythrocyte is shaped like a-

a) spherical 

b) convex 

c) concave 

d) bi-concave 

Answer: (d)

Explanation: The peripheral proteins of an erythrocyte’s plasma membrane are found on the internal surface and form a fibrillar membrane skeleton, which is important in defining the erythrocyte’s bi-concave shape.

7.Mutations in a membrane protein cause which of the following hereditary diseases?

a) Alzheimer’s disease 

b) Parkinson’s disease 

c) Anaemia 

d) Hemolytic anaemia 

Answer: (d)

Explanation: Hemolytic anaemia is characterised by aberrant erythrocyte morphologies, which have been linked to abnormalities in plasma membrane proteins present in erythrocytes called ankyrin or spectrin.

8. Which of the following diseases is Glycophorin involved in?

a) viral fever 

b) common cold 

c) asthma 

d) malaria 

Answer: (d)

Explanation: Glycophorin is a receptor used by the parasitic protozoan that causes malaria to gain access to blood cells. Those who lack glycophorin A and B are thus resistant to the illness.

9. The plasma membrane does not have this role-

(a) Energy transduction

(b) Intercellular interactions

(c) Responding to external stimuli

(d) Assisting in chromosome segregation

Answer: (d)

10. Of carbohydrates, the plasma membrane membrane-

(a) always faces outwards extracellular space

(b) directed to all sides in the membrane randomly

(c) always faces to the lumen of cells

(d) always faces inward to the nonpolar portion of membrane

Answer: (a)

11. Glycolipids are commonly found in the plasma membrane in the following locations: 

(a) cannot be predicted, it varies according to the cell types

(b) inner leaflet of plasma membrane

(c) outer leaflet of plasma membrane

(d) evenly distributed in both outer and inner leaves of plasma membrane

Answer: (c)

12. The main interaction responsible for plasma membrane stabilisation- 

(a) hydrophobic interactions

(b) hydrophilic interactions

(c) covalent bonds

(d) ionic bonds

Answer: (a)

13. Lipid molecules are distributed in the plasma membrane in the following ways: 

(a) head parallel

(b) alternate

(c) scattered

(d) series

Answer: (a)

14. Ion carriers may be found in the following places:

 (a) Plasma membranes

(b) Cell wall

(c) Nucleus

(d) Cellular space

Answer: (a)

15. In plasma membrane, the best way to know the characteristics of membrane proteins is-

(a) atomic force microscopy

(b) freeze fracture analysis and electron microscopy

(c) cryo-sectioning and electron microscopy

(d) all of the above

Answer: (b)

16.This layer is found closest to the plasma membrane in plant cells.

(a) Tonoplast

(b) Middle lamella

(c) secondary wall

(d) primary wall

Answer: (c)

17. Anthocyanin does not come out of beet root when stored in cold water because the plasma membrane is

(a) Dead

(b) differentially permeable

(c) permeable to anthocyanins

(d) Impermeable to anthocyanins

Answer: (d) 

18. Plasma membrane consists of-

(a) A protein, a lipid and a cellulose layer

(b) Bimolecular lipid layer surrounded by protein layers

(c) A protein layer between two lipid layers

(d) A lipid layer between two protein layers

Answer: (b)