PORTAGE BIOD 101 FINAL EXAM QUESTIONS
WITH ANSWERS AND EXPLANATIONS
Question 1.
In a living system, what is the major role of trophic levels?
A. synthesize polypeptide chains from nucleotide-coded information
B. organize food webs and clarify energy flow through ecosystems
C. couple energy-releasing processes to cellular work
D. build the electrochemical gradient used by ATP synthase
Correct Answer: B. organize food webs and clarify energy flow through
ecosystems
Explanation: The selected answer accurately describes trophic levels: organize food
webs and clarify energy flow through ecosystems. In this concept, feeding positions
describe transfer of matter and energy from producers through consumers, which helps
explain its role to organize food webs and clarify energy flow through ecosystems. The
distractors belong to other biological ideas; its broader significance is that trophic
structure helps explain why high-level predators are generally less abundant.
Question 2.
Which statement best explains the significance of proteins to living systems?
A. protein shape connects genetic information to cellular structure and function
B. meiosis links sexual reproduction to recombination and independent assortment
C. trophic structure helps explain why high-level predators are generally less abundant
D. sorting ensures newly made molecules reach appropriate cellular destinations
Correct Answer: A. protein shape connects genetic information to cellular
structure and function
Explanation: The selected answer accurately describes proteins: protein shape connects
genetic information to cellular structure and function. In this concept, amino-acid polymers
fold into specific three-dimensional structures, which helps explain its role to act as
enzymes, receptors, antibodies, channels, motors, and structural elements. The distractors
belong to other biological ideas; its broader significance is that protein shape connects
genetic information to cellular structure and function.
,Question 3.
Which statement best describes the central biological principle of lipids?
A. adenosine triphosphate transfers usable chemical energy through phosphate-group
reactions
B. biological catalysts lower activation energy without being consumed in the net reaction
C. a diverse group of hydrophobic or amphipathic molecules includes triglycerides,
phospholipids, and steroids
D. light energy is converted into chemical energy that supports carbon fixation
Correct Answer: C. a diverse group of hydrophobic or amphipathic molecules
includes triglycerides, phospholipids, and steroids
Explanation: The selected answer accurately describes lipids: a diverse group of
hydrophobic or amphipathic molecules includes triglycerides, phospholipids, and steroids.
In this concept, a diverse group of hydrophobic or amphipathic molecules includes
triglycerides, phospholipids, and steroids, which helps explain its role to store energy, form
membranes, insulate, and serve as signaling precursors. The distractors belong to other
biological ideas; its broader significance is that lipid chemistry underlies long-term energy
storage and biological membranes.
Question 4.
Which statement best explains the significance of DNA double helix to living systems?
A. nuclear organization separates transcription from cytoplasmic translation
B. receptor specificity allows targeted communication among cells
C. ATP couples catabolism to biosynthesis, transport, and mechanical work
D. complementarity enables accurate information storage and copying
Correct Answer: D. complementarity enables accurate information storage and
copying
Explanation: The selected answer accurately describes DNA double helix:
complementarity enables accurate information storage and copying. In this concept, two
antiparallel nucleotide strands pair through complementary bases and form a double helix,
which helps explain its role to provide a stable yet readable structure for genetic
information. The distractors belong to other biological ideas; its broader significance is that
complementarity enables accurate information storage and copying.
Question 5.
Which result would be predicted from changing the conditions that affect ATP?
A. severe ATP depletion impairs membrane pumps and cellular homeostasis
B. if only the treatment group changes under controlled conditions, the manipulation
becomes a stronger causal explanation
C. blocking RNA polymerase reduces production of newly transcribed RNAs
D. denaturation can disrupt function without necessarily breaking every peptide bond
Correct Answer: A. severe ATP depletion impairs membrane pumps and cellular
homeostasis
,Explanation: The selected answer accurately describes ATP: severe ATP depletion
impairs membrane pumps and cellular homeostasis. In this concept, adenosine
triphosphate transfers usable chemical energy through phosphate-group reactions, which
helps explain its role to couple energy-releasing processes to cellular work. The distractors
belong to other biological ideas; its broader significance is that ATP couples catabolism to
biosynthesis, transport, and mechanical work.
Question 6.
Which statement best explains the significance of DNA replication to living systems?
A. mitochondrial function links oxygen use to efficient ATP generation
B. accurate replication preserves genetic continuity between cell generations
C. active transport is essential for membrane potential, nutrient uptake, and homeostasis
D. immune memory is the biological basis for many vaccines
Correct Answer: B. accurate replication preserves genetic continuity between
cell generations
Explanation: The selected answer accurately describes DNA replication: accurate
replication preserves genetic continuity between cell generations. In this concept,
semiconservative copying produces daughter DNA molecules containing one parental and
one new strand, which helps explain its role to duplicate the genome before cell division.
The distractors belong to other biological ideas; its broader significance is that accurate
replication preserves genetic continuity between cell generations.
Question 7.
Which outcome depends most directly on the normal function of ATP?
A. produce population adaptation when environments consistently favor particular
inherited traits
B. synthesize polypeptide chains from nucleotide-coded information
C. move small molecules toward equilibrium
D. couple energy-releasing processes to cellular work
Correct Answer: D. couple energy-releasing processes to cellular work
Explanation: The selected answer accurately describes ATP: couple energy-releasing
processes to cellular work. In this concept, adenosine triphosphate transfers usable
chemical energy through phosphate-group reactions, which helps explain its role to couple
energy-releasing processes to cellular work. The distractors belong to other biological
ideas; its broader significance is that ATP couples catabolism to biosynthesis, transport,
and mechanical work.
, Question 8.
Which location is most appropriate for DNA replication?
A. where water can cross a membrane but relevant solutes are restricted
B. the nucleus for most eukaryotic nuclear genes
C. primarily in the nucleus of eukaryotic cells during S phase
D. throughout the cytoplasm with an inner membrane folded into cristae
Correct Answer: C. primarily in the nucleus of eukaryotic cells during S phase
Explanation: The selected answer accurately describes DNA replication: primarily in the
nucleus of eukaryotic cells during S phase. In this concept, semiconservative copying
produces daughter DNA molecules containing one parental and one new strand, which
helps explain its role to duplicate the genome before cell division. The distractors belong
to other biological ideas; its broader significance is that accurate replication preserves
genetic continuity between cell generations.
Question 9.
Which statement correctly addresses a common misconception about simple diffusion?
A. equilibrium does not mean molecules stop moving; it means opposing fluxes are
balanced
B. prokaryotic does not mean lacking genetic material or ribosomes
C. water does not move toward lower solute concentration in ordinary osmosis
D. a protein's function is not determined solely by the number of amino acids it contains
Correct Answer: A. equilibrium does not mean molecules stop moving; it means
opposing fluxes are balanced
Explanation: The selected answer accurately describes simple diffusion: equilibrium does
not mean molecules stop moving; it means opposing fluxes are balanced. In this concept,
particles move down their concentration gradient without direct cellular energy input,
which helps explain its role to move small molecules toward equilibrium. The distractors
belong to other biological ideas; its broader significance is that diffusion explains passive
movement of gases and lipid-soluble molecules.
Question 10.
Which statement best explains the significance of natural selection to living systems?
A. carbohydrates provide fuel intermediates and participate in cell-surface recognition
B. natural selection explains adaptation without requiring purposeful change
C. lipid chemistry underlies long-term energy storage and biological membranes
D. protein shape connects genetic information to cellular structure and function
Correct Answer: B. natural selection explains adaptation without requiring
purposeful change
Explanation: The selected answer accurately describes natural selection: natural
selection explains adaptation without requiring purposeful change. In this concept,
heritable variation that affects reproductive success changes trait frequencies over
WITH ANSWERS AND EXPLANATIONS
Question 1.
In a living system, what is the major role of trophic levels?
A. synthesize polypeptide chains from nucleotide-coded information
B. organize food webs and clarify energy flow through ecosystems
C. couple energy-releasing processes to cellular work
D. build the electrochemical gradient used by ATP synthase
Correct Answer: B. organize food webs and clarify energy flow through
ecosystems
Explanation: The selected answer accurately describes trophic levels: organize food
webs and clarify energy flow through ecosystems. In this concept, feeding positions
describe transfer of matter and energy from producers through consumers, which helps
explain its role to organize food webs and clarify energy flow through ecosystems. The
distractors belong to other biological ideas; its broader significance is that trophic
structure helps explain why high-level predators are generally less abundant.
Question 2.
Which statement best explains the significance of proteins to living systems?
A. protein shape connects genetic information to cellular structure and function
B. meiosis links sexual reproduction to recombination and independent assortment
C. trophic structure helps explain why high-level predators are generally less abundant
D. sorting ensures newly made molecules reach appropriate cellular destinations
Correct Answer: A. protein shape connects genetic information to cellular
structure and function
Explanation: The selected answer accurately describes proteins: protein shape connects
genetic information to cellular structure and function. In this concept, amino-acid polymers
fold into specific three-dimensional structures, which helps explain its role to act as
enzymes, receptors, antibodies, channels, motors, and structural elements. The distractors
belong to other biological ideas; its broader significance is that protein shape connects
genetic information to cellular structure and function.
,Question 3.
Which statement best describes the central biological principle of lipids?
A. adenosine triphosphate transfers usable chemical energy through phosphate-group
reactions
B. biological catalysts lower activation energy without being consumed in the net reaction
C. a diverse group of hydrophobic or amphipathic molecules includes triglycerides,
phospholipids, and steroids
D. light energy is converted into chemical energy that supports carbon fixation
Correct Answer: C. a diverse group of hydrophobic or amphipathic molecules
includes triglycerides, phospholipids, and steroids
Explanation: The selected answer accurately describes lipids: a diverse group of
hydrophobic or amphipathic molecules includes triglycerides, phospholipids, and steroids.
In this concept, a diverse group of hydrophobic or amphipathic molecules includes
triglycerides, phospholipids, and steroids, which helps explain its role to store energy, form
membranes, insulate, and serve as signaling precursors. The distractors belong to other
biological ideas; its broader significance is that lipid chemistry underlies long-term energy
storage and biological membranes.
Question 4.
Which statement best explains the significance of DNA double helix to living systems?
A. nuclear organization separates transcription from cytoplasmic translation
B. receptor specificity allows targeted communication among cells
C. ATP couples catabolism to biosynthesis, transport, and mechanical work
D. complementarity enables accurate information storage and copying
Correct Answer: D. complementarity enables accurate information storage and
copying
Explanation: The selected answer accurately describes DNA double helix:
complementarity enables accurate information storage and copying. In this concept, two
antiparallel nucleotide strands pair through complementary bases and form a double helix,
which helps explain its role to provide a stable yet readable structure for genetic
information. The distractors belong to other biological ideas; its broader significance is that
complementarity enables accurate information storage and copying.
Question 5.
Which result would be predicted from changing the conditions that affect ATP?
A. severe ATP depletion impairs membrane pumps and cellular homeostasis
B. if only the treatment group changes under controlled conditions, the manipulation
becomes a stronger causal explanation
C. blocking RNA polymerase reduces production of newly transcribed RNAs
D. denaturation can disrupt function without necessarily breaking every peptide bond
Correct Answer: A. severe ATP depletion impairs membrane pumps and cellular
homeostasis
,Explanation: The selected answer accurately describes ATP: severe ATP depletion
impairs membrane pumps and cellular homeostasis. In this concept, adenosine
triphosphate transfers usable chemical energy through phosphate-group reactions, which
helps explain its role to couple energy-releasing processes to cellular work. The distractors
belong to other biological ideas; its broader significance is that ATP couples catabolism to
biosynthesis, transport, and mechanical work.
Question 6.
Which statement best explains the significance of DNA replication to living systems?
A. mitochondrial function links oxygen use to efficient ATP generation
B. accurate replication preserves genetic continuity between cell generations
C. active transport is essential for membrane potential, nutrient uptake, and homeostasis
D. immune memory is the biological basis for many vaccines
Correct Answer: B. accurate replication preserves genetic continuity between
cell generations
Explanation: The selected answer accurately describes DNA replication: accurate
replication preserves genetic continuity between cell generations. In this concept,
semiconservative copying produces daughter DNA molecules containing one parental and
one new strand, which helps explain its role to duplicate the genome before cell division.
The distractors belong to other biological ideas; its broader significance is that accurate
replication preserves genetic continuity between cell generations.
Question 7.
Which outcome depends most directly on the normal function of ATP?
A. produce population adaptation when environments consistently favor particular
inherited traits
B. synthesize polypeptide chains from nucleotide-coded information
C. move small molecules toward equilibrium
D. couple energy-releasing processes to cellular work
Correct Answer: D. couple energy-releasing processes to cellular work
Explanation: The selected answer accurately describes ATP: couple energy-releasing
processes to cellular work. In this concept, adenosine triphosphate transfers usable
chemical energy through phosphate-group reactions, which helps explain its role to couple
energy-releasing processes to cellular work. The distractors belong to other biological
ideas; its broader significance is that ATP couples catabolism to biosynthesis, transport,
and mechanical work.
, Question 8.
Which location is most appropriate for DNA replication?
A. where water can cross a membrane but relevant solutes are restricted
B. the nucleus for most eukaryotic nuclear genes
C. primarily in the nucleus of eukaryotic cells during S phase
D. throughout the cytoplasm with an inner membrane folded into cristae
Correct Answer: C. primarily in the nucleus of eukaryotic cells during S phase
Explanation: The selected answer accurately describes DNA replication: primarily in the
nucleus of eukaryotic cells during S phase. In this concept, semiconservative copying
produces daughter DNA molecules containing one parental and one new strand, which
helps explain its role to duplicate the genome before cell division. The distractors belong
to other biological ideas; its broader significance is that accurate replication preserves
genetic continuity between cell generations.
Question 9.
Which statement correctly addresses a common misconception about simple diffusion?
A. equilibrium does not mean molecules stop moving; it means opposing fluxes are
balanced
B. prokaryotic does not mean lacking genetic material or ribosomes
C. water does not move toward lower solute concentration in ordinary osmosis
D. a protein's function is not determined solely by the number of amino acids it contains
Correct Answer: A. equilibrium does not mean molecules stop moving; it means
opposing fluxes are balanced
Explanation: The selected answer accurately describes simple diffusion: equilibrium does
not mean molecules stop moving; it means opposing fluxes are balanced. In this concept,
particles move down their concentration gradient without direct cellular energy input,
which helps explain its role to move small molecules toward equilibrium. The distractors
belong to other biological ideas; its broader significance is that diffusion explains passive
movement of gases and lipid-soluble molecules.
Question 10.
Which statement best explains the significance of natural selection to living systems?
A. carbohydrates provide fuel intermediates and participate in cell-surface recognition
B. natural selection explains adaptation without requiring purposeful change
C. lipid chemistry underlies long-term energy storage and biological membranes
D. protein shape connects genetic information to cellular structure and function
Correct Answer: B. natural selection explains adaptation without requiring
purposeful change
Explanation: The selected answer accurately describes natural selection: natural
selection explains adaptation without requiring purposeful change. In this concept,
heritable variation that affects reproductive success changes trait frequencies over
