BIOLOGY 189 COMPLETE EXAM TEST BANK
QUESTIONS WITH VERIFIED ANSWERS &
RATIONALES 2025-2026 EDITION
This comprehensive 200-question exam test bank
delivers premium, verified practice material covering
core cell biology, energetics, and molecular genetics
concepts for Biology 189. Every multiple-choice question
features exact, italicized answers paired with detailed,
bold-italicized rationales to guarantee maximum
conceptual clarity. Perfect for students striving to master
high-yield topics, build test-taking confidence, and
achieve top grades in their 2025/2026 biology
examinations.
Question 1 (Cell Theory)
Which of the following statements is a core tenet of
the modern cell theory?
A) All cells contain a nucleus and membrane-bound
organelles.
B) Cells can arise spontaneously from non-living
organic matter.
C) All living organisms are composed of one or
more cells.
D) Cells are the smallest structures capable of
,surviving without an energy source.
Answer: C
Rationale: Cell theory states that all living
organisms are made of cells, cells are the basic
unit of life, and all cells arise from pre-existing
cells. Option A applies only to eukaryotes, Option B
describes spontaneous generation (which cell
theory disproves), and Option D is incorrect
because cells require continuous energy inputs.
Question 2 (Biomolecules)
Which type of chemical bond is formed between two
amino acids during a dehydration synthesis reaction
to build a protein?
A) Hydrogen bond
B) Peptide bond
C) Ionic bond
D) Phosphodiester bond
Answer: B
Rationale: A peptide bond is a specific type of
covalent bond linking the carboxyl group of one
amino acid to the amino group of another. Hydrogen
bonds stabilize secondary/tertiary structures, ionic
bonds involve electron transfer, and phosphodiester
bonds link nucleotides in nucleic acids.
,Question 3 (Enzyme Kinetics)
How does a competitive inhibitor affect an enzyme-
catalyzed reaction?
A) It binds to the active site and prevents the
substrate from binding.
B) It binds to an allosteric site, altering the shape of
the active site.
C) It permanently denatures the enzyme’s tertiary
structure.
D) It increases the activation energy required for
the reaction to proceed.
Answer: A
Rationale: Competitive inhibitors mimic the
substrate and directly compete for the active site.
Non-competitive inhibitors bind to allosteric sites
(Option B). Inhibitors do not change the fundamental
activation energy of the un-catalyzed path (Option
D), they just restrict enzyme availability.
Question 4 (Cell Structure)
Which organelle contains hydrolytic enzymes
responsible for degrading old organelles and
foreign debris?
A) Peroxisome
B) Lysosome
, C) Golgi apparatus
D) Smooth Endoplasmic Reticulum
Answer: B
Rationale: Lysosomes are the waste-disposal and
recycling centers of animal cells, packed with acid
hydrolases. Peroxisomes handle oxidative reactions
and break down fatty acids/hydrogen peroxide.
Question 5 (Membrane Transport)
A red blood cell placed in a hypotonic solution will
exhibit which of the following responses?
A) Shrivel and crenate due to water loss.
B) Remain unchanged because the solute
concentration is equal.
C) Swell and potentially lyse due to water influx.
D) Actively pump out ions to achieve equilibrium.
Answer: C
Rationale: Hypotonic solutions have a lower solute
concentration (higher water concentration) than the
inside of the cell. Water moves down its gradient via
osmosis into the cell, causing it to swell and burst
(lyse).
Question 6 (Cellular Respiration)
QUESTIONS WITH VERIFIED ANSWERS &
RATIONALES 2025-2026 EDITION
This comprehensive 200-question exam test bank
delivers premium, verified practice material covering
core cell biology, energetics, and molecular genetics
concepts for Biology 189. Every multiple-choice question
features exact, italicized answers paired with detailed,
bold-italicized rationales to guarantee maximum
conceptual clarity. Perfect for students striving to master
high-yield topics, build test-taking confidence, and
achieve top grades in their 2025/2026 biology
examinations.
Question 1 (Cell Theory)
Which of the following statements is a core tenet of
the modern cell theory?
A) All cells contain a nucleus and membrane-bound
organelles.
B) Cells can arise spontaneously from non-living
organic matter.
C) All living organisms are composed of one or
more cells.
D) Cells are the smallest structures capable of
,surviving without an energy source.
Answer: C
Rationale: Cell theory states that all living
organisms are made of cells, cells are the basic
unit of life, and all cells arise from pre-existing
cells. Option A applies only to eukaryotes, Option B
describes spontaneous generation (which cell
theory disproves), and Option D is incorrect
because cells require continuous energy inputs.
Question 2 (Biomolecules)
Which type of chemical bond is formed between two
amino acids during a dehydration synthesis reaction
to build a protein?
A) Hydrogen bond
B) Peptide bond
C) Ionic bond
D) Phosphodiester bond
Answer: B
Rationale: A peptide bond is a specific type of
covalent bond linking the carboxyl group of one
amino acid to the amino group of another. Hydrogen
bonds stabilize secondary/tertiary structures, ionic
bonds involve electron transfer, and phosphodiester
bonds link nucleotides in nucleic acids.
,Question 3 (Enzyme Kinetics)
How does a competitive inhibitor affect an enzyme-
catalyzed reaction?
A) It binds to the active site and prevents the
substrate from binding.
B) It binds to an allosteric site, altering the shape of
the active site.
C) It permanently denatures the enzyme’s tertiary
structure.
D) It increases the activation energy required for
the reaction to proceed.
Answer: A
Rationale: Competitive inhibitors mimic the
substrate and directly compete for the active site.
Non-competitive inhibitors bind to allosteric sites
(Option B). Inhibitors do not change the fundamental
activation energy of the un-catalyzed path (Option
D), they just restrict enzyme availability.
Question 4 (Cell Structure)
Which organelle contains hydrolytic enzymes
responsible for degrading old organelles and
foreign debris?
A) Peroxisome
B) Lysosome
, C) Golgi apparatus
D) Smooth Endoplasmic Reticulum
Answer: B
Rationale: Lysosomes are the waste-disposal and
recycling centers of animal cells, packed with acid
hydrolases. Peroxisomes handle oxidative reactions
and break down fatty acids/hydrogen peroxide.
Question 5 (Membrane Transport)
A red blood cell placed in a hypotonic solution will
exhibit which of the following responses?
A) Shrivel and crenate due to water loss.
B) Remain unchanged because the solute
concentration is equal.
C) Swell and potentially lyse due to water influx.
D) Actively pump out ions to achieve equilibrium.
Answer: C
Rationale: Hypotonic solutions have a lower solute
concentration (higher water concentration) than the
inside of the cell. Water moves down its gradient via
osmosis into the cell, causing it to swell and burst
(lyse).
Question 6 (Cellular Respiration)
