Cells

Question 1

Which organelle is considered the ‘powerhouse’ of the cell?
A. Nucleus
B. Lysosome
C. Mitochondrion
D. Ribosome

Answer 1

C. Mitochondrion – Produces ATP, the energy currency of the cell.

Mitochondria are essential for energy production through cellular respiration.

Question 2

What is the function of ribosomes?
A. Store genetic material
B. Synthesise proteins
C. Detoxify harmful substances
D. Digest cellular waste

Answer 2

B. Synthesize proteins – Ribosomes are responsible for protein synthesis.

Ribosomes can be found free in the cytoplasm or attached to the rough endoplasmic reticulum.

Question 3

Which structure controls the movement of substances in and out of the cell?
A. Cytoplasm
B. Nucleolus
C. Plasma membrane
D. Endoplasmic reticulum

Answer 3

C. Plasma membrane – Controls entry and exit of substances.

The plasma membrane is selectively permeable, allowing certain molecules to pass while blocking others.

Question 4

The primary function of the rough endoplasmic reticulum is to:
A. Produce ATP
B. Store lipids
C. Synthesise proteins
D. Transport waste out of the cell

Answer 4

C. Synthesize proteins – Rough ER has ribosomes that make proteins.

The rough ER is involved in the synthesis of proteins destined for secretion or for use in the cell membrane.

Question 5

What type of cellular transport requires ATP?
A. Diffusion
B. Osmosis
C. Active transport
D. Facilitated diffusion

Answer 5

C. Active transport – Requires ATP to move substances against a gradient.

Active transport is essential for maintaining concentration gradients across membranes.

Question 6

The sodium-potassium pump moves:
A. Sodium into the cell and potassium out
B. Potassium into the cell and sodium out
C. Sodium and potassium equally in both directions
D. Only sodium into the cell

Answer 6

B. Potassium into the cell and sodium out – This maintains cell membrane potential.

The sodium-potassium pump is crucial for nerve impulse transmission and muscle contraction.

Question 7

Which cellular process describes a cell engulfing a large particle?
A. Exocytosis
B. Pinocytosis
C. Phagocytosis
D. Osmosis

Answer 7

C. Phagocytosis – Engulfing of large particles like bacteria.

Phagocytosis is a type of endocytosis specifically for large particles.

Question 8

Which cell junction prevents substances from passing between cells?
A. Desmosomes
B. Gap junctions
C. Tight junctions

Answer 8

C. Tight junctions – Prevent substances from passing between cells.

Tight junctions are important in epithelial tissues, providing a barrier to protect underlying tissues.

Question 9

What is the main component of the plasma membrane?
A. Carbohydrates
B. Cholesterol
C. Proteins
D. Phospholipids

Answer 9

D. Phospholipids – Major component of the plasma membrane.

Phospholipids form a bilayer that is fundamental to the structure of the plasma membrane.

Question 10

In which type of solution would a cell swell and possibly burst?
A. Hypertonic
B. Hypotonic
C. Isotonic
D. None of the above

Answer 10

B. Hypotonic – Water moves into the cell, causing it to swell.

A hypotonic solution has a lower solute concentration compared to the inside of the cell.

Question 11

What is the function of lysosomes?
A. Store genetic material
B. Detoxify harmful substances
C. Digest cellular waste and debris
D. Synthesize proteins

Answer 11

C. Digest cellular waste and debris – Lysosomes contain digestive enzymes.

Lysosomes are often referred to as the cell’s ‘clean-up crew.’

Question 12

Which structure is responsible for modifying and packaging proteins?
A. Golgi apparatus
B. Ribosome
C. Smooth endoplasmic reticulum
D. Nucleolus

Answer 12

A. Golgi apparatus – Modifies, packages, and ships proteins.

The Golgi apparatus is key in processing proteins synthesized in the rough ER.

Question 13

Microvilli are important because they:
A. Move substances across the cell surface
B. Propel the cell
C. Increase surface area for absorption
D. Act as a storage site for nutrients

Answer 13

C. Increase surface area for absorption – Found in the intestines.

Microvilli enhance the absorptive capacity of epithelial cells.

Question 14

What type of muscle cells have desmosomes to prevent tearing under stress?
A. Skeletal
B. Cardiac
C. Smooth
D. None of the above

Answer 14

B. Cardiac – Desmosomes prevent cardiac muscle cells from tearing.

Desmosomes provide mechanical strength to tissues subjected to stretching.

Question 15

Which of the following best describes osmosis?
A. Movement of water from a low to high solute concentration
B. Movement of solutes through a membrane
C. Active transport of molecules
D. Movement of water from high to low solute concentration

Answer 15

D. Movement of water from high to low solute concentration – This is osmosis.

Osmosis is crucial for maintaining cell turgor pressure.

Question 16

Which organelle is responsible for lipid metabolism and detoxification?
A. Ribosomes
B. Smooth endoplasmic reticulum
C. Golgi apparatus
D. Peroxisomes

Answer 16

B. Smooth endoplasmic reticulum – Involved in lipid metabolism and detoxification.

The smooth ER also plays a role in calcium storage and hormone synthesis.

Question 17

Which organelle assists in cell division?
A. Nucleus
B. Centrioles
C. Lysosomes
D. Mitochondria

Answer 17

B. Centrioles – Help organize microtubules during mitosis.

Centrioles play a critical role in the formation of the mitotic spindle.

Question 18

The primary function of gap junctions is to:
A. Allow direct communication between cells
B. Prevent leakage between cells
C. Bind cells together to prevent separation
D. Store calcium for muscle contraction

Answer 18

A. Allow direct communication between cells – Found in cardiac and smooth muscle.

Gap junctions facilitate the passage of ions and small molecules between adjacent cells.

Question 19

Which of the following is an example of passive transport?
A. Endocytosis
B. Active transport
C. Diffusion
D. Sodium-potassium pump

Answer 19

C. Diffusion – Passive movement of molecules down a concentration gradient.

Passive transport processes do not require energy from the cell.

Question 20

Which organelle is involved in apoptosis (programmed cell death)?
A. Nucleus
B. Mitochondria
C. Lysosomes
D. Centrioles

Answer 20

C. Lysosomes – Contain enzymes that aid in programmed cell death.

Apoptosis is a critical process for development and maintaining homeostasis.

Question 21

Which of the following is NOT a principle of the Cell Theory?
A. All living things are composed of cells
B. The cell is the basic unit of life
C. Cells can arise spontaneously
D. All cells come from pre-existing cells

Answer 21

C. Cells can arise spontaneously

The Cell Theory states that all cells arise from pre-existing cells, contradicting spontaneous generation.

Question 22

What is the primary function of the nucleus?
A. Synthesising proteins
B. Controlling cellular activities and storing genetic material
C. Producing ATP
D. Transporting substances

Answer 22

B. Controlling cellular activities and storing genetic material

The nucleus contains DNA, which directs cell functions and stores genetic information.

Question 23

Which structure is responsible for the production of ribosomes?
A. Nucleolus
B. Rough ER
C. Golgi apparatus
D. Centrioles

Answer 23

A. Nucleolus

The nucleolus, located inside the nucleus, produces ribosomes.

Question 24

Which of the following is NOT found in the plasma membrane?
A. Phospholipids
B. Proteins
C. DNA
D. Cholesterol

Answer 24

C. DNA

DNA is located in the nucleus, not in the plasma membrane.

Question 25

What role does cholesterol play in the plasma membrane? A. Provides structure and stability B. Acts as a receptor for signalling molecules C. Facilitates the movement of ions D. Synthesises proteins

Answer 25

A. Provides structure and stability ## Footnote Cholesterol helps maintain the fluidity and stability of the plasma membrane.

Question 26

Which organelle is involved in detoxification and lipid metabolism? A. Rough ER B. Smooth ER C. Golgi apparatus D. Ribosomes

Answer 26

B. Smooth ER ## Footnote The smooth endoplasmic reticulum is responsible for lipid metabolism and detoxification of harmful substances.

Question 27

Which of the following is an example of active transport? A. Osmosis B. Simple diffusion C. Sodium-potassium pump D. Facilitated diffusion

Answer 27

C. Sodium-potassium pump ## Footnote Active transport requires energy (ATP), and the sodium-potassium pump moves ions against their concentration gradient.

Question 28

Which type of cell junction allows communication between adjacent cells? A. Tight junctions B. Desmosomes C. Gap junctions D. Plasmodesmata

Answer 28

C. Gap junctions ## Footnote Gap junctions allow direct communication between cells by enabling the passage of ions and molecules.

Question 29

What happens to a cell placed in a hypertonic solution? A. It swells B. It shrinks C. It remains the same D. It bursts

Answer 29

B. It shrinks ## Footnote In a hypertonic solution, water moves out of the cell, causing it to shrink (crenation).

Question 30

What process describes the movement of molecules from an area of higher concentration to an area of lower concentration? A. Active transport B. Endocytosis C. Diffusion D. Exocytosis

Answer 30

C. Diffusion ## Footnote Diffusion is the passive movement of molecules from an area of high concentration to low concentration.

Question 31

Which of the following best describes exocytosis? A. A cell engulfs a solid particle B. A cell takes in fluid and dissolved substances C. A cell expels substances using vesicles D. Movement of solutes across the membrane without energy

Answer 31

C. A cell expels substances using vesicles ## Footnote Exocytosis is a process in which vesicles transport and release substances outside the cell.

Question 32

Which cytoskeletal component is the largest and functions in intracellular transport? A. Microfilaments B. Intermediate filaments C. Microtubules D. Centrioles

Answer 32

C. Microtubules ## Footnote Microtubules are the largest cytoskeletal elements and serve as tracks for intracellular transport.

Question 33

Which organelle contains digestive enzymes to break down waste? A. Golgi apparatus B. Lysosome C. Mitochondrion D. Ribosome

Answer 33

B. Lysosome ## Footnote Lysosomes contain hydrolytic enzymes that break down cellular debris and waste materials.

Question 34

Which type of transport requires membrane proteins but does not require ATP? A. Simple diffusion B. Facilitated diffusion C. Active transport D. Exocytosis

Answer 34

B. Facilitated diffusion ## Footnote Facilitated diffusion moves molecules through membrane proteins without using energy.

Question 35

What is the primary role of peroxisomes? A. Protein synthesis B. Detoxifying harmful substances C. Producing ATP D. Storing nutrients

Answer 35

B. Detoxifying harmful substances ## Footnote Peroxisomes help detoxify harmful substances such as hydrogen peroxide.

Question 36

Which organelle is responsible for processing and packaging proteins? A. Ribosomes B. Nucleus C. Golgi apparatus D. Smooth ER

Answer 36

C. Golgi apparatus ## Footnote The Golgi apparatus modifies, sorts, and packages proteins for secretion or transport.

Question 37

Which type of transport moves substances against a concentration gradient? A. Diffusion B. Osmosis C. Facilitated diffusion D. Active transport

Answer 37

D. Active transport ## Footnote Active transport requires ATP to move substances against their concentration gradient.

Question 38

Which organelle is known as the ‘recycling centre’ of the cell? A. Lysosome B. Peroxisome C. Golgi apparatus D. Ribosome

Answer 38

A. Lysosome ## Footnote Lysosomes digest and recycle cellular waste and worn-out organelles.

Question 39

The glycocalyx on the cell membrane plays a role in: A. Cell recognition and adhesion B. Energy production C. Protein synthesis D. Detoxification

Answer 39

A. Cell recognition and adhesion ## Footnote The glycocalyx is a carbohydrate-rich coating that helps cells recognize each other and adhere.

Question 40

The movement of water across a selectively permeable membrane is called: A. Diffusion B. Osmosis C. Facilitated diffusion D. Endocytosis

Answer 40

B. Osmosis ## Footnote Osmosis is the passive movement of water across a selectively permeable membrane from low to high solute concentration.

Question 41

What letter represents lysosomes?

Answer 41

K

Question 42

Which function would be most directly impacted by a disorder affecting the nucleolus? A. ATP production B. Protein synthesis C. DNA replication D. Plasma membrane integrity

Answer 42

B. Protein synthesis ## Footnote The nucleolus is responsible for ribosome synthesis, which is essential for protein production.

Question 43

What characteristic of the phospholipid bilayer allows for selective permeability? A. Hydrophilic heads forming interior of the membrane B. Hydrophobic tails preventing water soluble molecules from crossing C. The presence of ribosomes within the membrane D. The direct attachment of DNA to membrane proteins

Answer 43

B. Hydrophobic tails preventing water-soluble molecules from crossing ## Footnote The hydrophobic tails in the bilayer’s center repel water-soluble substances.

Question 44

What is the expected cellular response to IV fluids with a hypotonic solution (0.45% NaCl)? A. Cells will shrink due to water loss B. Cells will swell due to water influx C. No net movement of water D. Sodium will diffuse into cells, causing hypertonicity

Answer 44

B. Cells will swell due to water influx ## Footnote Hypotonic solutions have lower solute concentration than intracellular fluid, causing water to move into cells.

Question 45

What describes the key difference between facilitated diffusion and active transport? A. Facilitated diffusion requires ATP, while active transport does not B. Active transport moves molecules against their concentration gradient C. Both processes involve movement from high to low concentration D. Facilitated diffusion only occurs in prokaryotic cells

Answer 45

B. Active transport moves molecules against their concentration gradient ## Footnote Facilitated diffusion is passive and moves molecules down the gradient.

Question 46

What is the impact on cellular transport due to a mutation affecting a chloride channel in cystic fibrosis? A. Increased passive diffusion of sodium into the cell B. Accumulation of mucus due to defective chloride transport C. Unregulated glucose transport across the membrane D. Decreased protein synthesis in the nucleus

Answer 46

B. Accumulation of mucus due to defective chloride transport ## Footnote CFTR gene mutations disrupt chloride ion transport, preventing water movement.

Question 47

What process would be primarily affected by a medication that inhibits mitochondrial function? A. DNA replication B. Protein synthesis C. ATP production D. Membrane transport

Answer 47

C. ATP production ## Footnote Mitochondria generate ATP via cellular respiration.

Question 48

Why are liver cells rich in smooth endoplasmic reticulum? A. They synthesise large amounts of protein B. They produce digestive enzymes C. They detoxify substances like alcohol D. They store calcium for muscle connection

Answer 48

C. They detoxify substances like alcohol ## Footnote Smooth ER is involved in detoxification of drugs, alcohol, and toxins.

Question 49

A mutation in tRNA would primarily affect which process? A. DNA replication B. Transcription C. Translation D. Glycolysis

Answer 49

B. Translation ## Footnote tRNA carries amino acids to the ribosome during translation.

Question 50

How do lysosomes contribute to immune function? A. They secrete antibodies into the bloodstream B. They engulf pathogens and digest them with enzymes C. They store oxygen for cellular reproduction D. They transport neurotransmitters between neurons

Answer 50

B. They engulf pathogens and digest them with enzymes ## Footnote Lysosomes break down pathogens engulfed by white blood cells.

Question 51

What symptom would a patient experiencing mitochondrial dysfunction likely exhibit? A. Muscle weakness and fatigue B. Increased cell division C. Enhanced protein synthesis D. Thickened mucus secretions

Answer 51

A. Muscle weakness and fatigue ## Footnote Mitochondrial diseases lead to ATP depletion, resulting in muscle fatigue.