Test Bank for Corrections In The
21St Century, 2024
1. The plasma membrane is composed primarily of which two macromolecules? A. Proteins and
lipids B. Lipids and carbohydrates C. Proteins and nucleic acids D. Nucleic acids and carbohydrates -
ANSWERSA. Proteins and lipids - The membrane is mostly phospholipids with embedded proteins
that control transport and signaling.
2. The hydrophobic tails of phospholipids face which direction in the membrane bilayer? A. Toward
water B. Toward each other C. Toward cytoplasm D. Toward extracellular fluid - ANSWERSB. Toward
each other - Nonpolar tails face inward to avoid water, forming the bilayer's core.
3. Which type of membrane transport requires ATP? A. Simple diffusion B. Facilitated diffusion C.
Osmosis D. Active transport - ANSWERSD. Active transport - Moves substances against their gradient
using ATP.
4. The Na+/K+ pump moves ions in what ratio? A. 2 Na+ in, 3 K+ out B. 3 Na+ out, 2 K+ in C. 1 Na+
out, 1 K+ in D. 4 Na+ in, 3 K+ out - ANSWERSB. 3 Na+ out, 2 K+ in - Maintains resting membrane
potential by pumping Na+ out and K+ in.
5. Which molecule passes most easily through a plasma membrane? A. Water B. Glucose C. Oxygen
D. Sodium ion - ANSWERSC. Oxygen - Small nonpolar molecules diffuse freely through the lipid
bilayer.
6. Facilitated diffusion requires what? A. ATP B. Transport protein C. Vesicle formation D. Receptor
binding - ANSWERSB. Transport protein - Carrier or channel proteins allow polar molecules to cross.
7. Osmosis refers specifically to the movement of A. Solute B. Water C. Proteins D. Ions - ANSWERSB.
Water - Moves from low solute to high solute concentration.
8. A red blood cell placed in a hypotonic solution will A. Shrink B. Swell C. Stay the same D. Lyse then
shrink - ANSWERSB. Swell - Water enters the cell due to higher internal solute concentration.
9. A red blood cell placed in a hypertonic solution will A. Swell B. Shrink C. Stay the same D. Divide -
ANSWERSB. Shrink - Water leaves the cell due to higher external solute concentration.
,10. The resting membrane potential is primarily established by A. Calcium channels B. Na+/K+
ATPase C. Chloride diffusion D. Proton pumps - ANSWERSB. Na+/K+ ATPase - Maintains ion gradients
responsible for resting potential.
11. Which cellular structure synthesizes proteins? A. Lysosome B. Ribosome C. Nucleus D. Golgi
apparatus - ANSWERSB. Ribosome - Links amino acids based on mRNA codons.
12. Rough ER is termed "rough" because of the presence of A. Ribosomes B. Lysosomes C. Lipids D.
Vesicles - ANSWERSA. Ribosomes - Attach to its surface for protein synthesis.
13. The smooth ER functions mainly in A. Protein packaging B. Lipid synthesis and detoxification C.
DNA replication D. Protein translation - ANSWERSB. Lipid synthesis and detoxification - Produces
phospholipids and detoxifies compounds.
14. The Golgi apparatus functions to A. Produce energy B. Modify, sort, and package proteins C.
Synthesize RNA D. Store calcium - ANSWERSB. Modify, sort, and package proteins - Prepares
molecules for secretion or transport.
15. Mitochondria are known as the "powerhouse" because they A. Store calcium B. Generate ATP C.
Produce lipids D. Digest macromolecules - ANSWERSB. Generate ATP - Perform oxidative
phosphorylation for energy.
16. The process of bringing material into the cell by forming vesicles from the plasma membrane is
called A. Exocytosis B. Endocytosis C. Osmosis D. Diffusion - ANSWERSB. Endocytosis - Internalizes
extracellular materials via vesicles.
17. The process of releasing vesicular contents to the outside of the cell is A. Phagocytosis B.
Exocytosis C. Pinocytosis D. Facilitated diffusion - ANSWERSB. Exocytosis - Vesicles fuse with plasma
membrane to secrete contents.
18. Which organelle contains digestive enzymes? A. Ribosome B. Lysosome C. Golgi apparatus D.
Peroxisome - ANSWERSB. Lysosome - Breaks down waste and damaged organelles.
19. Which cytoskeletal element provides tensile strength and resists stretching? A. Microtubules B.
Intermediate filaments C. Microfilaments D. Actin - ANSWERSB. Intermediate filaments - Provide
structural support to maintain shape.
, 20. The sodium-potassium pump is an example of which type of transport? A. Passive B. Active C.
Facilitated diffusion D. Osmotic - ANSWERSB. Active - Requires ATP to move ions against their
gradient.
21. Which of the following is TRUE of diffusion? A. It requires ATP B. Molecules move from low to
high concentration C. It depends on random molecular motion D. It stops once equilibrium is
reached - ANSWERSC. It depends on random molecular motion - Passive process toward equilibrium.
22. The phospholipid head is A. Hydrophobic B. Nonpolar C. Hydrophilic D. Lipid-soluble -
ANSWERSC. Hydrophilic - The polar head interacts with water.
23. What maintains the separation of charge across the plasma membrane? A. Mitochondria B.
Voltage-gated channels C. Ion pumps and leak channels D. Ribosomes - ANSWERSC. Ion pumps and
leak channels - Maintain potential differences.
24. The primary function of cilia is to A. Move the cell B. Move substances across the cell surface C.
Increase surface area D. Detect environmental changes - ANSWERSB. Move substances across the
cell surface - Coordinated beating moves mucus or fluids.
25. Which organelle packages hydrolytic enzymes? A. Ribosome B. Rough ER C. Golgi apparatus D.
Lysosome - ANSWERSC. Golgi apparatus - Packages lysosomal enzymes into vesicles.
26. The nuclear envelope contains A. Ribosomes only B. Nuclear pores C. Centrioles D. Mitochondria
- ANSWERSB. Nuclear pores - Regulate exchange between nucleus and cytoplasm.
27. Chromatin is composed of A. RNA and lipids B. DNA and proteins C. Carbohydrates and RNA D.
Protein only - ANSWERSB. DNA and proteins - DNA wound around histones.
28. The nucleolus is the site of A. mRNA transcription B. rRNA synthesis C. DNA replication D. Protein
translation - ANSWERSB. rRNA synthesis - Assembles ribosomal subunits.
29. The cytosol is best described as A. The fluid inside organelles B. The intracellular fluid between
organelles C. The extracellular fluid D. The plasma membrane - ANSWERSB. The intracellular fluid
between organelles - Supports reactions and transport.
30. What organelle is abundant in liver cells for detoxification? A. Smooth ER B. Rough ER C. Golgi D.
Lysosome - ANSWERSA. Smooth ER - Detoxifies drugs and metabolizes lipids.
21St Century, 2024
1. The plasma membrane is composed primarily of which two macromolecules? A. Proteins and
lipids B. Lipids and carbohydrates C. Proteins and nucleic acids D. Nucleic acids and carbohydrates -
ANSWERSA. Proteins and lipids - The membrane is mostly phospholipids with embedded proteins
that control transport and signaling.
2. The hydrophobic tails of phospholipids face which direction in the membrane bilayer? A. Toward
water B. Toward each other C. Toward cytoplasm D. Toward extracellular fluid - ANSWERSB. Toward
each other - Nonpolar tails face inward to avoid water, forming the bilayer's core.
3. Which type of membrane transport requires ATP? A. Simple diffusion B. Facilitated diffusion C.
Osmosis D. Active transport - ANSWERSD. Active transport - Moves substances against their gradient
using ATP.
4. The Na+/K+ pump moves ions in what ratio? A. 2 Na+ in, 3 K+ out B. 3 Na+ out, 2 K+ in C. 1 Na+
out, 1 K+ in D. 4 Na+ in, 3 K+ out - ANSWERSB. 3 Na+ out, 2 K+ in - Maintains resting membrane
potential by pumping Na+ out and K+ in.
5. Which molecule passes most easily through a plasma membrane? A. Water B. Glucose C. Oxygen
D. Sodium ion - ANSWERSC. Oxygen - Small nonpolar molecules diffuse freely through the lipid
bilayer.
6. Facilitated diffusion requires what? A. ATP B. Transport protein C. Vesicle formation D. Receptor
binding - ANSWERSB. Transport protein - Carrier or channel proteins allow polar molecules to cross.
7. Osmosis refers specifically to the movement of A. Solute B. Water C. Proteins D. Ions - ANSWERSB.
Water - Moves from low solute to high solute concentration.
8. A red blood cell placed in a hypotonic solution will A. Shrink B. Swell C. Stay the same D. Lyse then
shrink - ANSWERSB. Swell - Water enters the cell due to higher internal solute concentration.
9. A red blood cell placed in a hypertonic solution will A. Swell B. Shrink C. Stay the same D. Divide -
ANSWERSB. Shrink - Water leaves the cell due to higher external solute concentration.
,10. The resting membrane potential is primarily established by A. Calcium channels B. Na+/K+
ATPase C. Chloride diffusion D. Proton pumps - ANSWERSB. Na+/K+ ATPase - Maintains ion gradients
responsible for resting potential.
11. Which cellular structure synthesizes proteins? A. Lysosome B. Ribosome C. Nucleus D. Golgi
apparatus - ANSWERSB. Ribosome - Links amino acids based on mRNA codons.
12. Rough ER is termed "rough" because of the presence of A. Ribosomes B. Lysosomes C. Lipids D.
Vesicles - ANSWERSA. Ribosomes - Attach to its surface for protein synthesis.
13. The smooth ER functions mainly in A. Protein packaging B. Lipid synthesis and detoxification C.
DNA replication D. Protein translation - ANSWERSB. Lipid synthesis and detoxification - Produces
phospholipids and detoxifies compounds.
14. The Golgi apparatus functions to A. Produce energy B. Modify, sort, and package proteins C.
Synthesize RNA D. Store calcium - ANSWERSB. Modify, sort, and package proteins - Prepares
molecules for secretion or transport.
15. Mitochondria are known as the "powerhouse" because they A. Store calcium B. Generate ATP C.
Produce lipids D. Digest macromolecules - ANSWERSB. Generate ATP - Perform oxidative
phosphorylation for energy.
16. The process of bringing material into the cell by forming vesicles from the plasma membrane is
called A. Exocytosis B. Endocytosis C. Osmosis D. Diffusion - ANSWERSB. Endocytosis - Internalizes
extracellular materials via vesicles.
17. The process of releasing vesicular contents to the outside of the cell is A. Phagocytosis B.
Exocytosis C. Pinocytosis D. Facilitated diffusion - ANSWERSB. Exocytosis - Vesicles fuse with plasma
membrane to secrete contents.
18. Which organelle contains digestive enzymes? A. Ribosome B. Lysosome C. Golgi apparatus D.
Peroxisome - ANSWERSB. Lysosome - Breaks down waste and damaged organelles.
19. Which cytoskeletal element provides tensile strength and resists stretching? A. Microtubules B.
Intermediate filaments C. Microfilaments D. Actin - ANSWERSB. Intermediate filaments - Provide
structural support to maintain shape.
, 20. The sodium-potassium pump is an example of which type of transport? A. Passive B. Active C.
Facilitated diffusion D. Osmotic - ANSWERSB. Active - Requires ATP to move ions against their
gradient.
21. Which of the following is TRUE of diffusion? A. It requires ATP B. Molecules move from low to
high concentration C. It depends on random molecular motion D. It stops once equilibrium is
reached - ANSWERSC. It depends on random molecular motion - Passive process toward equilibrium.
22. The phospholipid head is A. Hydrophobic B. Nonpolar C. Hydrophilic D. Lipid-soluble -
ANSWERSC. Hydrophilic - The polar head interacts with water.
23. What maintains the separation of charge across the plasma membrane? A. Mitochondria B.
Voltage-gated channels C. Ion pumps and leak channels D. Ribosomes - ANSWERSC. Ion pumps and
leak channels - Maintain potential differences.
24. The primary function of cilia is to A. Move the cell B. Move substances across the cell surface C.
Increase surface area D. Detect environmental changes - ANSWERSB. Move substances across the
cell surface - Coordinated beating moves mucus or fluids.
25. Which organelle packages hydrolytic enzymes? A. Ribosome B. Rough ER C. Golgi apparatus D.
Lysosome - ANSWERSC. Golgi apparatus - Packages lysosomal enzymes into vesicles.
26. The nuclear envelope contains A. Ribosomes only B. Nuclear pores C. Centrioles D. Mitochondria
- ANSWERSB. Nuclear pores - Regulate exchange between nucleus and cytoplasm.
27. Chromatin is composed of A. RNA and lipids B. DNA and proteins C. Carbohydrates and RNA D.
Protein only - ANSWERSB. DNA and proteins - DNA wound around histones.
28. The nucleolus is the site of A. mRNA transcription B. rRNA synthesis C. DNA replication D. Protein
translation - ANSWERSB. rRNA synthesis - Assembles ribosomal subunits.
29. The cytosol is best described as A. The fluid inside organelles B. The intracellular fluid between
organelles C. The extracellular fluid D. The plasma membrane - ANSWERSB. The intracellular fluid
between organelles - Supports reactions and transport.
30. What organelle is abundant in liver cells for detoxification? A. Smooth ER B. Rough ER C. Golgi D.
Lysosome - ANSWERSA. Smooth ER - Detoxifies drugs and metabolizes lipids.
