Biology 202 Exam Questions and Correct
Answers
Intercellular signaling
A) usually initiates with binding of a signal molecule to its receptor.
B) usually terminates with binding of a signal molecule to its receptor.
C) usually initiates with binding of a second messenger molecule to its cell surface receptor.
D) usually terminates with binding of a second messenger molecule to its cell surface receptor.
E) occurs in animals, but never in plants. - CORRECT ANSWER✅✅✅A) usually initiates
with binding of a signal molecule to its receptor.
Selective advantages of cell signaling is
A) to ensure timing of communication between cells in different parts of an organism.
B) to ensure that crucial activities occur in the right cells at the right time.
C) it allows some organisms to evolve without a nervous system.
D) A and B are correct.
E) A, B, and C are correct. - CORRECT ANSWER✅✅✅E) A, B, and C are correct.
A receptor protein that recognizes a chemical signal is most similar to
A) a catalytic site of an enzyme binding to a substrate.
B) a chlorophyll molecule absorbing a photon.
C) DNA transferring information to RNA.
D) RNA transferring information to protein.
E) individual genes combining into a chromosome. - CORRECT ANSWER✅✅✅A) a
catalytic site of an enzyme binding to a substrate.
A small molecule that specifically binds to a larger one
A) is a side chain.
B) is a receptor.
,C) is a polymer.
D) is a ligand.
E) is a satellite. - CORRECT ANSWER✅✅✅D) is a ligand.
Inhibition of the ability of an animal cell to produce GTP
A) would not allow activation and inactivation of G proteins on the cytoplasmic side of the
plasma membrane.
B) would not affect signal reception and transduction, but would block cellular responses to
these signals.
C) would compel the cells to use their A proteins instead of the G proteins.
D) would have no effect on signal transduction.
E) would make the signal transduction more efficient as energy-rich ATP will be used instead of
GTP. - CORRECT ANSWER✅✅✅A) would not allow activation and inactivation of G
proteins on the cytoplasmic side of the plasma membrane.
The research to better control cholera, a serious disease, should focus on
A) the effect of the cholera toxin on G proteins in humans.
B) the effect of the cholera toxin on tyrosine-kinase receptors in humans.
C) the effect of the cholera toxin on synaptic signaling in humans.
D) the effect of the cholera toxin on multiplication of bacteria within human cells.
E) the effect of the cholera toxin on attachment of bacteria to human cells. - CORRECT
ANSWER✅✅✅A) the effect of the cholera toxin on G proteins in humans.
Tyrosine-kinase receptors
A) induce yeast mating.
B) are a class of GTP G-protein signal receptors.
C) are not found in humans.
D) attach phosphates to specific amino acids.
E) remove phosphates from specific amino acids. - CORRECT ANSWER✅✅✅D) attach
phosphates to specific amino acids.
,Ligand-gated ion channels
A) function as gates for protein transport into the cell.
B) open or close in response to a chemical signal.
C) are nuclear pores.
D) open and close regularly even in the absence of a chemical signal.
E) connect cells together within tissues. - CORRECT ANSWER✅✅✅B) open or close in
response to a chemical signal.
An enzyme that transfers phosphate groups from ATP to tyrosine residues within a protein is
called
A) tyrosine ATPase.
B) tyrosinase.
C) tyrosine phosphatase.
D) tyrosine kinase.
E) ATP synthase. - CORRECT ANSWER✅✅✅D) tyrosine kinase.
Which of the following is/are considered a secondary messenger?
A) cAMP
B) calcium ions
C) hormone
D) A and B are correct
E) A and
C are correct - CORRECT ANSWER✅✅✅D) A and B are correct
Which of the following molecules is NOT normally oxidized in aerobic respiration to generate
ATP?
A) lipids
B) nucleic acids
, C) amino acids
D) sugars
E) proteins - CORRECT ANSWER✅✅✅B) nucleic acids
Which statement(s) below support the idea that glycolysis is one of the most ancient of metabolic
processes?
A) If run in reverse, glycolysis will build glucose molecules.
B) Glycolysis neither uses nor needs oxygen.
C) The enzymes of glycolysis are found in the cytosol rather than in a membrane-enclosed
organelle.
D) A and B are correct
E) B and C are correct - CORRECT ANSWER✅✅✅E) B and C are correct
Which enzyme in cellular respiration is primarily responsible for producing ATP?
A) ATPase
B) ATP dehydrogenase
C) ATP synthase
D) ATP kinase
E) ATP phosphatase - CORRECT ANSWER✅✅✅C) ATP synthase
DNP is a molecule that causes membranes to become more permeable to protons. What would
happen to an animal that is injected with this substance?
A) There will be no effect because protons will combine with hydroxyls into water.
B) More ATP will be produced and the animal will become hyperactive.
C) The animal would develop a muscle disease because the muscle cell membranes will be
dissolved.
D) Less ATP will be produced and the animal will become hypoactive.
E) The animal will retain water and become bloated because protons will combine with
hydroxyls into water molecules. - CORRECT ANSWER✅✅✅D) Less ATP will be
produced and the animal will become hypoactive.
Answers
Intercellular signaling
A) usually initiates with binding of a signal molecule to its receptor.
B) usually terminates with binding of a signal molecule to its receptor.
C) usually initiates with binding of a second messenger molecule to its cell surface receptor.
D) usually terminates with binding of a second messenger molecule to its cell surface receptor.
E) occurs in animals, but never in plants. - CORRECT ANSWER✅✅✅A) usually initiates
with binding of a signal molecule to its receptor.
Selective advantages of cell signaling is
A) to ensure timing of communication between cells in different parts of an organism.
B) to ensure that crucial activities occur in the right cells at the right time.
C) it allows some organisms to evolve without a nervous system.
D) A and B are correct.
E) A, B, and C are correct. - CORRECT ANSWER✅✅✅E) A, B, and C are correct.
A receptor protein that recognizes a chemical signal is most similar to
A) a catalytic site of an enzyme binding to a substrate.
B) a chlorophyll molecule absorbing a photon.
C) DNA transferring information to RNA.
D) RNA transferring information to protein.
E) individual genes combining into a chromosome. - CORRECT ANSWER✅✅✅A) a
catalytic site of an enzyme binding to a substrate.
A small molecule that specifically binds to a larger one
A) is a side chain.
B) is a receptor.
,C) is a polymer.
D) is a ligand.
E) is a satellite. - CORRECT ANSWER✅✅✅D) is a ligand.
Inhibition of the ability of an animal cell to produce GTP
A) would not allow activation and inactivation of G proteins on the cytoplasmic side of the
plasma membrane.
B) would not affect signal reception and transduction, but would block cellular responses to
these signals.
C) would compel the cells to use their A proteins instead of the G proteins.
D) would have no effect on signal transduction.
E) would make the signal transduction more efficient as energy-rich ATP will be used instead of
GTP. - CORRECT ANSWER✅✅✅A) would not allow activation and inactivation of G
proteins on the cytoplasmic side of the plasma membrane.
The research to better control cholera, a serious disease, should focus on
A) the effect of the cholera toxin on G proteins in humans.
B) the effect of the cholera toxin on tyrosine-kinase receptors in humans.
C) the effect of the cholera toxin on synaptic signaling in humans.
D) the effect of the cholera toxin on multiplication of bacteria within human cells.
E) the effect of the cholera toxin on attachment of bacteria to human cells. - CORRECT
ANSWER✅✅✅A) the effect of the cholera toxin on G proteins in humans.
Tyrosine-kinase receptors
A) induce yeast mating.
B) are a class of GTP G-protein signal receptors.
C) are not found in humans.
D) attach phosphates to specific amino acids.
E) remove phosphates from specific amino acids. - CORRECT ANSWER✅✅✅D) attach
phosphates to specific amino acids.
,Ligand-gated ion channels
A) function as gates for protein transport into the cell.
B) open or close in response to a chemical signal.
C) are nuclear pores.
D) open and close regularly even in the absence of a chemical signal.
E) connect cells together within tissues. - CORRECT ANSWER✅✅✅B) open or close in
response to a chemical signal.
An enzyme that transfers phosphate groups from ATP to tyrosine residues within a protein is
called
A) tyrosine ATPase.
B) tyrosinase.
C) tyrosine phosphatase.
D) tyrosine kinase.
E) ATP synthase. - CORRECT ANSWER✅✅✅D) tyrosine kinase.
Which of the following is/are considered a secondary messenger?
A) cAMP
B) calcium ions
C) hormone
D) A and B are correct
E) A and
C are correct - CORRECT ANSWER✅✅✅D) A and B are correct
Which of the following molecules is NOT normally oxidized in aerobic respiration to generate
ATP?
A) lipids
B) nucleic acids
, C) amino acids
D) sugars
E) proteins - CORRECT ANSWER✅✅✅B) nucleic acids
Which statement(s) below support the idea that glycolysis is one of the most ancient of metabolic
processes?
A) If run in reverse, glycolysis will build glucose molecules.
B) Glycolysis neither uses nor needs oxygen.
C) The enzymes of glycolysis are found in the cytosol rather than in a membrane-enclosed
organelle.
D) A and B are correct
E) B and C are correct - CORRECT ANSWER✅✅✅E) B and C are correct
Which enzyme in cellular respiration is primarily responsible for producing ATP?
A) ATPase
B) ATP dehydrogenase
C) ATP synthase
D) ATP kinase
E) ATP phosphatase - CORRECT ANSWER✅✅✅C) ATP synthase
DNP is a molecule that causes membranes to become more permeable to protons. What would
happen to an animal that is injected with this substance?
A) There will be no effect because protons will combine with hydroxyls into water.
B) More ATP will be produced and the animal will become hyperactive.
C) The animal would develop a muscle disease because the muscle cell membranes will be
dissolved.
D) Less ATP will be produced and the animal will become hypoactive.
E) The animal will retain water and become bloated because protons will combine with
hydroxyls into water molecules. - CORRECT ANSWER✅✅✅D) Less ATP will be
produced and the animal will become hypoactive.
