Test Bank Biology Concepts and Applications 10th Edition Cecie Starr Christine
Evers Lisa Starr Updated 2026/2027 with Solution questions and answers 100 +
A researcher is investigating how enzymes function under different
environmental conditions. During an experiment, the temperature is gradually
increased beyond the enzyme’s optimal range, and a sharp decline in activity is
observed. What is the most likely molecular explanation for this decrease in
enzyme activity?
A. Increased substrate concentration
B. Denaturation of the enzyme’s tertiary structure
C. Enhanced binding at the active site
D. Increased ATP availability
Answer: B
Rationale: High temperatures disrupt hydrogen bonds and other interactions that
maintain the enzyme’s shape, causing denaturation and loss of function.
A student observes that when a plant is deprived of nitrogen, its leaves become
yellow and growth is stunted. What is the biological reason for this observation?
A. Nitrogen is required for chlorophyll production
1
,B. Nitrogen is used for water absorption
C. Nitrogen increases oxygen production
D. Nitrogen reduces respiration
Answer: A
Rationale: Nitrogen is essential for synthesizing chlorophyll and proteins;
deficiency leads to chlorosis (yellowing leaves).
A mutation occurs in a gene that encodes a membrane transport protein,
rendering it nonfunctional. Which immediate cellular effect is most likely?
A. Increased ATP production
B. Disrupted movement of specific molecules across the membrane
C. Enhanced DNA replication
D. Increased protein synthesis
Answer: B
Rationale: Transport proteins facilitate movement of substances across
membranes; dysfunction disrupts this process.
2
,A scientist is studying population genetics and notices that allele frequencies
change significantly after a few individuals colonize a new habitat. Which concept
explains this change?
A. Bottleneck effect
B. Founder effect
C. Natural selection
D. Mutation
Answer: B
Rationale: The founder effect occurs when a small group establishes a new
population, leading to reduced genetic variation.
During photosynthesis, a plant exposed to high light intensity but limited carbon
dioxide shows a decrease in glucose production. Why?
A. Light reactions stop completely
B. CO₂ is required for the Calvin cycle
C. Chlorophyll is destroyed
D. ATP production decreases
3
, Answer: B
Rationale: The Calvin cycle requires CO₂ to synthesize glucose; without it,
production slows.
A mutation in DNA results in no change to the amino acid sequence of a protein.
What type of mutation is this?
A. Missense
B. Nonsense
C. Silent
D. Frameshift
Answer: C
Rationale: Silent mutations do not alter the amino acid due to redundancy in the
genetic code.
A cell increases the number of lysosomes. What function is most likely enhanced?
A. Protein synthesis
4
Evers Lisa Starr Updated 2026/2027 with Solution questions and answers 100 +
A researcher is investigating how enzymes function under different
environmental conditions. During an experiment, the temperature is gradually
increased beyond the enzyme’s optimal range, and a sharp decline in activity is
observed. What is the most likely molecular explanation for this decrease in
enzyme activity?
A. Increased substrate concentration
B. Denaturation of the enzyme’s tertiary structure
C. Enhanced binding at the active site
D. Increased ATP availability
Answer: B
Rationale: High temperatures disrupt hydrogen bonds and other interactions that
maintain the enzyme’s shape, causing denaturation and loss of function.
A student observes that when a plant is deprived of nitrogen, its leaves become
yellow and growth is stunted. What is the biological reason for this observation?
A. Nitrogen is required for chlorophyll production
1
,B. Nitrogen is used for water absorption
C. Nitrogen increases oxygen production
D. Nitrogen reduces respiration
Answer: A
Rationale: Nitrogen is essential for synthesizing chlorophyll and proteins;
deficiency leads to chlorosis (yellowing leaves).
A mutation occurs in a gene that encodes a membrane transport protein,
rendering it nonfunctional. Which immediate cellular effect is most likely?
A. Increased ATP production
B. Disrupted movement of specific molecules across the membrane
C. Enhanced DNA replication
D. Increased protein synthesis
Answer: B
Rationale: Transport proteins facilitate movement of substances across
membranes; dysfunction disrupts this process.
2
,A scientist is studying population genetics and notices that allele frequencies
change significantly after a few individuals colonize a new habitat. Which concept
explains this change?
A. Bottleneck effect
B. Founder effect
C. Natural selection
D. Mutation
Answer: B
Rationale: The founder effect occurs when a small group establishes a new
population, leading to reduced genetic variation.
During photosynthesis, a plant exposed to high light intensity but limited carbon
dioxide shows a decrease in glucose production. Why?
A. Light reactions stop completely
B. CO₂ is required for the Calvin cycle
C. Chlorophyll is destroyed
D. ATP production decreases
3
, Answer: B
Rationale: The Calvin cycle requires CO₂ to synthesize glucose; without it,
production slows.
A mutation in DNA results in no change to the amino acid sequence of a protein.
What type of mutation is this?
A. Missense
B. Nonsense
C. Silent
D. Frameshift
Answer: C
Rationale: Silent mutations do not alter the amino acid due to redundancy in the
genetic code.
A cell increases the number of lysosomes. What function is most likely enhanced?
A. Protein synthesis
4
