Cell Membrane & Cell Wall — NEET Biology MCQs with Solutions
Free NEET Biology Cell Membrane & Cell Wall MCQs with step-by-step solutions (57 questions). Part of Cell: The Unit of Life. Practise online on Prepizo — no login needed.
▶ Practise Cell Membrane & Cell Wall online (free)
Questions with solutions
Q1 — Cell Membrane & Cell Wall · medium
The chemical studies on the cell membrane that deduced its possible structure were mostly done on which cells?
A. Human erythrocytes ✓ Correct
B. Platelets
C. Cheek cells
D. WBC
Solution: The detailed chemical studies of the cell membrane and the deduction of its possible structure were performed mainly on human red blood cells (erythrocytes), which lack internal organelles and are easily isolated.
Q2 — Cell Membrane & Cell Wall · medium
In the plasma membrane, the lipids have their polar heads facing
A. In the middle
B. Stable facing nowhere
C. Outer side ✓ Correct
D. Inner side
Solution: Membrane lipids are arranged so that the polar (hydrophilic) heads face the outer and inner aqueous sides, while the non-polar hydrophobic tails point towards the interior of the bilayer.
Q3 — Cell Membrane & Cell Wall · medium
The lipid component of the plasma membrane is mainly constituted of
A. Glycogen
B. All of these
C. Glycolipids
D. Phosphoglycerides ✓ Correct
Solution: The major lipids of the plasma membrane are phosphoglycerides (phospholipids). Glycogen is a storage polysaccharide and is not a membrane lipid.
Q4 — Cell Membrane & Cell Wall · medium
Which of the following is not a component of the plasma membrane?
A. Cholesterol
B. Protein
C. Sugar
D. None of these ✓ Correct
Solution: Sugars (as glycoproteins/glycolipids), proteins and cholesterol are all present in the plasma membrane, so none of the listed items is absent.
Q5 — Cell Membrane & Cell Wall · medium
What is the percentage of proteins and lipids respectively in an RBC membrane?
A. 52%, 42%
B. 50%, 40%
C. 52%, 40% ✓ Correct
D. 50%, 42%
Solution: Chemical analysis of the human RBC membrane showed it is made of about 52% proteins and 40% lipids.
Q6 — Cell Membrane & Cell Wall · medium
Which of the following membrane proteins lie on the surface of the cell membrane?
A. Integral proteins
B. Glycoproteins
C. Peripheral proteins ✓ Correct
D. Both (a) and (b)
Solution: Peripheral proteins lie on the surface of the membrane, whereas integral proteins are partially or totally buried in or span across the membrane.
Q7 — Cell Membrane & Cell Wall · medium
The ability of proteins to move laterally within the membrane is measured as
A. Mobility
B. Flexibility
C. None of these
D. Fluidity ✓ Correct
Solution: The quasi-fluid nature of lipids allows lateral movement of proteins within the bilayer; this ability is measured as the fluidity of the membrane.
Q8 — Cell Membrane & Cell Wall · medium
For what reason is the fluid nature of the membrane important?
A. Secretions
B. Endocytosis
C. Cell growth
D. All of these ✓ Correct
Solution: The fluidity of the membrane is important for many functions such as cell growth, secretion, endocytosis and cell division.
Q9 — Cell Membrane & Cell Wall · medium
The most important function of the plasma membrane is that it
A. Transports the molecules across ✓ Correct
B. Gives shape to the cell
C. Divides the cell
D. Both (a) and (b)
Solution: The most important function of the plasma membrane is the transport of molecules across it, which is selective (selectively permeable).
Q10 — Cell Membrane & Cell Wall · medium
In which kind of transport do molecules move across the membrane without the utilization of energy?
A. Osmosis
B. Both (a) and (b) ✓ Correct
C. Passive transport
D. Active transport
Solution: Passive transport (including osmosis of water) occurs down the concentration gradient and does not require expenditure of energy.
Q11 — Cell Membrane & Cell Wall · medium
Movement of water across the plasma membrane occurs by
A. Active transport
B. Passive transport
C. All of these
D. Osmosis ✓ Correct
Solution: Water moves across the plasma membrane by osmosis, which is a passive process (down its concentration gradient, requiring no energy).
Q12 — Cell Membrane & Cell Wall · medium
In which kind of transport do molecules move against the concentration gradient?
A. Active transport ✓ Correct
B. Facilitated transport
C. Passive transport
D. All of these
Solution: Active transport moves molecules against the concentration gradient and requires energy (e.g. the Na+-K+ pump).
Q13 — Cell Membrane & Cell Wall · medium
The plasma membrane consists mainly of
A. Proteins embedded in a phospholipid bilayer ✓ Correct
B. Proteins and carbohydrates only
C. Sugar embedded in glycolipids
D. Phospholipids embedded in a protein bilayer
Solution: According to the fluid mosaic model, the plasma membrane consists of proteins embedded in (or associated with) a phospholipid bilayer.
Q14 — Cell Membrane & Cell Wall · medium
The lipids of the plasma membrane are present as
A. Glycolipids
B. All of these ✓ Correct
C. Phospholipids
D. Sterols
Solution: Membrane lipids include phospholipids (mainly phosphoglycerides), sterols such as cholesterol, and glycolipids.
Q15 — Cell Membrane & Cell Wall · medium
The latest accepted model for the plasma membrane is the
A. Fluid mosaic model ✓ Correct
B. Unit membrane model
C. Lamellar model
D. Molecular lipid model
Solution: The fluid mosaic model, proposed by Singer and Nicolson (1972), is the currently accepted model of membrane structure.
Q16 — Cell Membrane & Cell Wall · medium
The fluid mosaic model of the plasma membrane is seen through
A. Electrophoresis
B. Electron microscopy ✓ Correct
C. Chromatography
D. Light microscopy
Solution: The ultrastructure of the membrane, as described by the fluid mosaic model, is revealed under the electron microscope.
Q17 — Cell Membrane & Cell Wall · medium
Which of the following lies on the surface of the plasma membrane?
A. Lipids
B. Peripheral proteins ✓ Correct
C. Both 1 and 2
D. Integral proteins
Solution: Peripheral proteins lie on the surface of the membrane, while integral proteins are buried in or span across the bilayer.
Q18 — Cell Membrane & Cell Wall · medium
The Na+-K+ pump is an example of
A. Active transport
B. Both 1 and 3 ✓ Correct
C. Passive transport
D. Transport which uses expenditure of energy
Solution: The Na+-K+ pump moves ions against their concentration gradients, which is active transport and requires expenditure of energy.
Q19 — Cell Membrane & Cell Wall · medium
Cell recognition and adhesion occur due to which component of the plasma membrane?
A. Cholesterol
B. Protein
C. Lipids
D. Glycocalyx ✓ Correct
Solution: Cell recognition and adhesion are mediated by the glycocalyx, the carbohydrate-rich (glycoprotein/glycolipid) coat on the outer surface of the membrane.
Q20 — Cell Membrane & Cell Wall · medium
The fluid nature of the membrane is important for
A. Secretion and endocytosis
B. All of these ✓ Correct
C. Cell division and growth
D. Formation of intercellular junctions
Solution: Membrane fluidity is essential for cell division and growth, secretion and endocytosis, and formation of intercellular junctions.
Q21 — Cell Membrane & Cell Wall · hard
The quasi-fluid nature of __________ enables __________ movement of proteins within the overall bilayer of a plasma membrane.
A. Protein, flip-flop
B. Protein, lateral
C. Lipid, flip-flop
D. Lipid, lateral ✓ Correct
Solution: The quasi-fluid nature of the lipid enables the lateral movement of proteins within the bilayer, which is measured as membrane fluidity.
Q22 — Cell Membrane & Cell Wall · hard
Which of the following is common to facilitated diffusion and active transport?
A. Occurs against the concentration gradient
B. Occurs along the concentration gradient
C. Energy requirement exists
D. Requirement of carrier protein ✓ Correct
Solution: Both facilitated diffusion and active transport require carrier (transport) proteins. Only active transport needs energy and moves against the gradient.
Q23 — Cell Membrane & Cell Wall · medium
What is the role of sterol (cholesterol) in the cell membrane?
A. Communication with other cells
B. Transport
C. Secretion
D. Stability ✓ Correct
Solution: Sterols such as cholesterol are inserted among the phospholipids and provide mechanical stability to the membrane.
Q24 — Cell Membrane & Cell Wall · medium
A transmembrane protein is present
A. On the inner surface of the cell membrane
B. In between the two layers of the cell membrane
C. Across the cell membrane ✓ Correct
D. On the outer surface of the cell membrane
Solution: A transmembrane (integral) protein spans completely across the lipid bilayer, from one surface to the other.
Q25 — Cell Membrane & Cell Wall · medium
Polar molecules move across the membrane by
A. Osmosis
B. Simple diffusion
C. Facilitated diffusion ✓ Correct
D. Active diffusion
Solution: Polar (hydrophilic) molecules cannot cross the hydrophobic bilayer directly, so they move across by facilitated diffusion using carrier proteins.
Q26 — Cell Membrane & Cell Wall · medium
Neutral solutes may move across the membrane by
A. Simple diffusion ✓ Correct
B. Facilitated diffusion
C. Osmosis
D. Active diffusion
Solution: Neutral (non-polar) solutes can pass directly through the lipid bilayer down their concentration gradient by simple diffusion.
Q27 — Cell Membrane & Cell Wall · hard
Transport across the membrane that is unaffected by oxygen, cyanide and temperature is called
A. Active transport
B. Ionic transport
C. None of these
D. Passive transport ✓ Correct
Solution: Passive transport does not require metabolic energy, so it is unaffected by oxygen supply, respiratory poisons like cyanide, or temperature; active transport is affected by these.
Q28 — Cell Membrane & Cell Wall · medium
The fluid mosaic model, an improved model of the structure of the cell membrane, was proposed by
A. Robertson
B. Singer and Nicolson (1972) ✓ Correct
C. Singer and Nicolson (1872)
D. All of the above
Solution: The fluid mosaic model of membrane structure was proposed by Singer and Nicolson in 1972.
Q29 — Cell Membrane & Cell Wall · medium
Cellulose, galactans, mannans and calcium carbonate are present in the cell wall of
A. Algae ✓ Correct
B. Higher plants
C. Fungi
D. Bacteria
Solution: The cell wall of algae is made of cellulose, galactans, mannans and mineral salts like calcium carbonate.
Q30 — Cell Membrane & Cell Wall · medium
Which of the following layers of the cell wall is capable of growth and gradually diminishes as the cell matures?
A. Primary cell wall ✓ Correct
B. Tertiary cell wall
C. Middle cell wall
D. Secondary cell wall
Solution: The primary cell wall of a young cell is capable of growth and gradually diminishes in thickness as the cell matures and the secondary wall is deposited.