,BIOD 102 Module 3 | Q&A | 2026/2027 | Essential Biology | Portage Learning
1. Signals travel along the length of which part of a neuron?
A) Dendrites
B) Cell body
C) Axon
D) Axon hillock
Correct Answer: Axon
Rationale: Signals travel along the length of the axon, which is the long projection of a
neuron that conducts electrical impulses away from the cell body. Dendrites receive
signals, the cell body integrates them, and the axon hillock is where action potentials are
initiated.
2. True or False: Vasoconstriction decreases the diameter of veins, thereby raising the
pressure within the vessels.
A) True
B) False
Correct Answer: False
Rationale: Vasoconstriction decreases the diameter of arterioles, not veins. This raises
pressure within the vessels by increasing resistance to blood flow. Vasoconstriction of
arterioles is a key mechanism for regulating blood pressure and flow.
3. What causes the "lub-dub" sound of the heart?
A) Contraction of the atria and ventricles
B) Blood flowing through the chambers
,C) Result of the four valves opening and closing
D) Electrical impulses from the SA node
Correct Answer: Result of the four valves opening and closing
Rationale: The "lub-dub" sound of the heart is caused by the opening and closing of the
four heart valves. The "lub" (S1) is from the closure of the atrioventricular valves, and the
"dub" (S2) is from the closure of the semilunar valves.
4. Nearly all animals rely on three main classes of molecules as sources of energy. What
are they?
A) Carbohydrates, proteins, and nucleic acids
B) Carbohydrates, lipids, and proteins
C) Lipids, proteins, and vitamins
D) Carbohydrates, lipids, and nucleic acids
Correct Answer: Carbohydrates, lipids, and proteins
Rationale: Nearly all animals rely on carbohydrates, lipids, and proteins as the three main
classes of molecules for energy. Carbohydrates provide quick energy, lipids store
concentrated energy, and proteins can be broken down for energy when needed.
5. The three main types of biological reactions are:
A) Redox, Metabolism, and Dehydration
B) Oxidation, Reduction, and Hydrolysis
C) Anabolism, Catabolism, and Synthesis
D) Dehydration, Hydrolysis, and Phosphorylation
, Correct Answer: Redox, Metabolism, and Dehydration
Rationale: The three types of biological reactions are Redox (oxidation-reduction),
Metabolism (which includes anabolism and catabolism), and Dehydration (synthesis
reactions that remove water). These are fundamental reaction types in biochemistry.
6. Which term refers to the sum of all energy-requiring (bond-forming) reactions in a cell?
A) Catabolism
B) Anabolism
C) Metabolism
D) Redox reaction
Correct Answer: Anabolism
Rationale: Anabolism is the sum of all energy-requiring reactions that build complex
molecules from simpler ones (bond-forming). Catabolism is the sum of energy-releasing
reactions (bond-breaking). Metabolism encompasses both.
7. Which term refers to the sum of all energy-releasing (bond-breaking) reactions in a cell?
A) Anabolism
B) Catabolism
C) Metabolism
D) Redox reaction
Correct Answer: Catabolism
1. Signals travel along the length of which part of a neuron?
A) Dendrites
B) Cell body
C) Axon
D) Axon hillock
Correct Answer: Axon
Rationale: Signals travel along the length of the axon, which is the long projection of a
neuron that conducts electrical impulses away from the cell body. Dendrites receive
signals, the cell body integrates them, and the axon hillock is where action potentials are
initiated.
2. True or False: Vasoconstriction decreases the diameter of veins, thereby raising the
pressure within the vessels.
A) True
B) False
Correct Answer: False
Rationale: Vasoconstriction decreases the diameter of arterioles, not veins. This raises
pressure within the vessels by increasing resistance to blood flow. Vasoconstriction of
arterioles is a key mechanism for regulating blood pressure and flow.
3. What causes the "lub-dub" sound of the heart?
A) Contraction of the atria and ventricles
B) Blood flowing through the chambers
,C) Result of the four valves opening and closing
D) Electrical impulses from the SA node
Correct Answer: Result of the four valves opening and closing
Rationale: The "lub-dub" sound of the heart is caused by the opening and closing of the
four heart valves. The "lub" (S1) is from the closure of the atrioventricular valves, and the
"dub" (S2) is from the closure of the semilunar valves.
4. Nearly all animals rely on three main classes of molecules as sources of energy. What
are they?
A) Carbohydrates, proteins, and nucleic acids
B) Carbohydrates, lipids, and proteins
C) Lipids, proteins, and vitamins
D) Carbohydrates, lipids, and nucleic acids
Correct Answer: Carbohydrates, lipids, and proteins
Rationale: Nearly all animals rely on carbohydrates, lipids, and proteins as the three main
classes of molecules for energy. Carbohydrates provide quick energy, lipids store
concentrated energy, and proteins can be broken down for energy when needed.
5. The three main types of biological reactions are:
A) Redox, Metabolism, and Dehydration
B) Oxidation, Reduction, and Hydrolysis
C) Anabolism, Catabolism, and Synthesis
D) Dehydration, Hydrolysis, and Phosphorylation
, Correct Answer: Redox, Metabolism, and Dehydration
Rationale: The three types of biological reactions are Redox (oxidation-reduction),
Metabolism (which includes anabolism and catabolism), and Dehydration (synthesis
reactions that remove water). These are fundamental reaction types in biochemistry.
6. Which term refers to the sum of all energy-requiring (bond-forming) reactions in a cell?
A) Catabolism
B) Anabolism
C) Metabolism
D) Redox reaction
Correct Answer: Anabolism
Rationale: Anabolism is the sum of all energy-requiring reactions that build complex
molecules from simpler ones (bond-forming). Catabolism is the sum of energy-releasing
reactions (bond-breaking). Metabolism encompasses both.
7. Which term refers to the sum of all energy-releasing (bond-breaking) reactions in a cell?
A) Anabolism
B) Catabolism
C) Metabolism
D) Redox reaction
Correct Answer: Catabolism
