MCQ on Plasma Membrane (Part-1): The plasma membrane, also known as the cell membrane, is a thin, semi-permeable barrier that surrounds the cell, separating its internal contents from the external environment. It is composed of a phospholipid bilayer with embedded proteins and controls the movement of substances in and out of the cell. This MCQ on Plasma Membrane will help you to study the Structure and Functions of cell membrane. For Part-2 Click here…
Cell & Molecular Biology Notes | Cell & Molecular Biology PPT
(1). The average thickness of plasma membrane of a eukaryotic cell is:
A. 5 to 10 nm
B. 5 to 10 Å
C. 5 to 10 µm
D. 5 to 10 pµm
(2). Which of the following is NOT the function of plasma membrane?
A. Intercellular interactions
B. Responding to external stimuli
C. Energy transduction
D. Assisting in chromosome segregation
(3). Which of the following statement is true regarding the surface tension of plasma membrane?
A. Surface tension of plasma membrane is more than pure lipid structures
B. Surface tension of plasma membrane is less than pure lipid structures
C. Surface tension of plasma membrane and pure lipid structures are same
D. Plasma membrane do not have surface tension
(4). Which of the following statements best describes the chemical composition of plasma membrane?
A. Plasma membrane is composed of two layers—one layer of phospholipids and one layer of proteins.
B. Plasma membrane is composed of equal numbers of phospholipids, proteins, and carbohydrates.
C. Plasma membrane is bilayers of proteins with associated lipids and carbohydrates.
D. Plasma membrane is bilayers of phospholipids with associated proteins and carbohydrates.
(5). Consider the following statements:
A. The polar portion of cholesterol is facing external to the membrane
B. Placement of cholesterol molecules in the membrane interfere the flexibility of lipids hydrocarbon chain
C. Cholesterol provide stiffness to membrane
D. Cholesterol is absent in plasma membrane of plants
E. Cholesterol is absent in bacterial plasma membrane
Which of the above statements are correct?
A. A, B, C, D, E
B. A, B, C, E
C. A, C, D, E
D. A, C, D, E
You may also like: Cell and Molecular Biology PPTs
(6). Biochemical analysis of a plasma membrane sample showed about 20 -25% cardiolipin content (a type of membrane lipid). Most probably the sample is from:
A. Human erythrocytes cell membrane
B. Myelin sheath of nerve cells
C. Mitochondrial inner membrane
D. Mitochondrial outer membrane
(7). Glycolipids in plasma membrane are usually located at:
A. Outer leaflet of plasma membrane
B. Inner leaflet of plasma membrane
C. Evenly distributed in both inner and outer leaves of plasma membrane
D. Cannot be predicted, it varies according to cell types
(8). Which of the following events in a biological membrane would not be energetically favorable and therefore not occur spontaneously?
A. the rotation of membrane proteins
B. the rotation of phospholipids
C. the lateral movement of phospholipids
D. the flip-flop of phospholipids to the opposite leaflet
(9). Malarial parasite uses ________ on the plasma membrane of RBC as receptor to enter in the cell
A. Band 3 protein
B. Glycophorins
C. Spectrin protein
D. Ankyrin proteins
(10). The carbohydrate content of plasma membrane in eukaryotes is:
A. 2 – 10 % by weight
B. 20 – 25% by weight
C. 30 – 50 % by weight
D. 60 – 70% by weight
You may also like: Cell & Molecular Biology Lecture Notes
(11). Carbohydrates in the plasma membrane:
A. Always face inward to the non-polar portion of membrane
B. Always face outward to extracellular space
C. Always face to the lumen of cells
D. Directed to all sides in the membrane randomly
(12). Muscular dystrophy, a devastating disease that cripple and kills children are caused by:
A. Mutation in dystrophin
B. Mutation in band 3 protein
C. Mutation in glycophorin A
D. Mutation in ankyrin
(13). Enzymes such as desaturase, phospholipase and acetyltransferase are very essential for maintaining the integrity of plasma membranes. These enzymes are involved in:
A. Maintaining the bilayer nature of membrane
B. Maintains the semi-permeability of membrane
C. Maintaining the fluidity of membrane
D. Maintain the position of trans-membrane proteins in the membrane
(14). A person having the enzyme which adds N-acetylgalactosamine to the end of glycolipids which determine the blood group. The blood group of the person will be
A. A
B. B
C. AB
D. O
(15). A person having the enzyme which adds galactose to the end of glycolipids which determine the blood group. The blood group of the person will be
A. A
B. B
C. AB
D. O
(16). Red blood cells in the blood repel each other due to:
A. The concave shape of RBC
B. They lack nucleus and other membrane structures
C. Carbohydrates moieties of glycophorin A in RBC membrane contain sialic acid residues
D. Amino acids in the peripheral portion of glycophorin A are negatively charged
(17). The main role of carbohydrates in the cell membrane is
A. Adhesion
B. Recognition
C. Locomotion
D. Reception
(18). The best method to study the properties of integral membrane proteins in the plasma membrane is
A. Cryo-sectioning and electron microscopy
B. Freeze fracture analysis and electron microscopy
C. Atomic force microscopy
D. All of these methods
(19). GPI anchored proteins are:
A. Peripheral proteins of plasma membrane
B. Integral proteins of plasma membrane
C. Proteins which randomly binds to the lipids of plasma membrane
D. Proteins which binds to ion gated channels in the plasma membrane
(20). The fluidity of plasma membrane increase with
A. Increase in saturated fatty acids in the membrane
B. Increase in unsaturated fatty acids in the membrane
C. Increase in phospholipid content in the membrane
D. Increase in glycolipid content in the membrane
Answer key and explanations…
1. Ans. (A). 5 to 10 nm
2. Ans. (D). Assisting in chromosome segregation
Learn more on: Membrane Lipids: Properties, Structure & Classification + PPT
Functions of plasma membrane: (1). Selective uptake and export of ions and molecules; (2). Cell compartmentalization; (3). Protein sorting; (4). Anchoring of the cytoskeleton; (5). Production of energy intermediates such as ATP and NADPH; (6). Cell signaling; (7). Cell and nuclear division; (8). Adhesion of cells to each other and to the extracellular matrix
3. Ans. (B). Surface tension of plasma membrane is less than pure lipid structures
This observation leads to the discovery of proteins in the membrane. The reduction in the surface tension of membrane than pure lipid structures is due the presence of proteins in the plasma membrane.
4. Ans. (D). Plasma membrane is bilayers of phospholipids with associated proteins and carbohydrates
5. Ans. (A). A, B, C, D
6. Ans. (D). Mitochondrial outer membrane
The only other place where cardiolipin can be found is the plasma membrane of bacteria. Presence of cardiolipin in the outer membrane of mitochondria is one of the strongest evidence for endosymbiont theory for the origin of mitochondria in eukaryotes.
7. Ans. (A). Outer leaflet of plasma membrane
They forms the glycocalyx of the cell
8. Ans. (D). The flip-flop of phospholipids to the opposite leaflet
9. Ans. (B). Glycophorins
10. Ans. (A). 2 – 10 % by weight
11. Ans. (B). Always face outward to extracellular space
12. Ans. (A). Mutation in Dystrophin
13. Ans. (C). Maintaining the fluidity of membrane
14. Ans. (A). A
15. Ans. (B). B
16. Ans. (C). Carbohydrates moieties of glycophorin A in RBC membrane contain sialic acid residues
17. Ans. (B). Recognition
18. Ans. (B). Freeze fracture analysis and electron microscopy
19. Ans. (A). Peripheral proteins of plasma membrane
20. Ans. (B). Increase in unsaturated fatty acids in the membrane
You may also like... NOTES QUESTION BANK COMPETITIVE EXAMS. PPTs UNIVERSITY EXAMS DIFFERENCE BETWEEN.. MCQs PLUS ONE BIOLOGY NEWS & JOBS MOCK TESTS PLUS TWO BIOLOGY PRACTICAL