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Portage Learning BIOD 101 Actual Exam
Questions and Answers with Rationales
2026/2027 | Essential Biology I Module 4 |
Cellular Biology | Pass Guarantee
Q001: In a laboratory setting, you observe a eukaryotic cell under a compound
microscope. Which organelle would appear as the most prominent, dark-staining
structure within the nucleus?
Options:
A. Rough endoplasmic reticulum
B. Golgi apparatus
C. Nucleolus
D. Mitochondria
Answer: C
Q002: During a cell fractionation experiment, which centrifugation technique
would be most appropriate to isolate intact mitochondria from a cell homogenate?
Options:
A. Low-speed centrifugation at 1,000xg
B. High-speed centrifugation at 10,000xg
C. Ultracentrifugation at 100,000xg
D. Differential centrifugation using multiple speeds
Answer: D
Q003: In a diffusion experiment using dialysis tubing, you place a glucose solution
inside the bag and immerse it in distilled water. Which factor would most
significantly increase the rate of glucose diffusion across the membrane?
Options:
, 2
A. Decreasing the temperature from 37°C to 25°C
B. Increasing the molecular weight of glucose
C. Increasing the concentration gradient
D. Decreasing the surface area of the membrane
Answer: C
Q004: When observing onion cells in a hypotonic solution under a microscope,
what cellular change would you expect to see?
Options:
A. Plasmolysis and cell shrinkage
B. No visible change
C. Turgor pressure increase and cell swelling
D. Cell membrane rupture
Answer: C
Q005: In a laboratory demonstration of active transport, which molecule would
require the most ATP consumption for transport across a cell membrane?
Options:
A. Oxygen moving down its concentration gradient
B. Water through aquaporins
C. Sodium ions pumped against their gradient
D. Carbon dioxide diffusing freely
Answer: C
Q006: During a spectrophotometry lab measuring enzyme activity, you observe
that the rate of product formation decreases as substrate concentration increases.
What is the most likely explanation?
Options:
, 3
A. The enzyme is being saturated with substrate
B. The enzyme is experiencing substrate inhibition
C. The temperature is too low
D. The pH is optimal
Answer: B
Q007: In a respirometer experiment measuring cellular respiration in yeast, which
gas would be consumed and cause the drop in pressure observed?
Options:
A. Carbon dioxide
B. Nitrogen
C. Oxygen
D. Hydrogen
Answer: C
Q008: When testing the products of cellular respiration in germinating peas, which
reagent would you use to confirm the presence of carbon dioxide production?
Options:
A. Benedict's solution
B. Biuret reagent
C. Bromothymol blue
D. Iodine solution
Answer: C
Q009: In a photosynthesis experiment using spinach leaves and DCPIP, what color
change would indicate that photosynthesis is occurring?
Options:
A. Blue to clear
Portage Learning BIOD 101 Actual Exam
Questions and Answers with Rationales
2026/2027 | Essential Biology I Module 4 |
Cellular Biology | Pass Guarantee
Q001: In a laboratory setting, you observe a eukaryotic cell under a compound
microscope. Which organelle would appear as the most prominent, dark-staining
structure within the nucleus?
Options:
A. Rough endoplasmic reticulum
B. Golgi apparatus
C. Nucleolus
D. Mitochondria
Answer: C
Q002: During a cell fractionation experiment, which centrifugation technique
would be most appropriate to isolate intact mitochondria from a cell homogenate?
Options:
A. Low-speed centrifugation at 1,000xg
B. High-speed centrifugation at 10,000xg
C. Ultracentrifugation at 100,000xg
D. Differential centrifugation using multiple speeds
Answer: D
Q003: In a diffusion experiment using dialysis tubing, you place a glucose solution
inside the bag and immerse it in distilled water. Which factor would most
significantly increase the rate of glucose diffusion across the membrane?
Options:
, 2
A. Decreasing the temperature from 37°C to 25°C
B. Increasing the molecular weight of glucose
C. Increasing the concentration gradient
D. Decreasing the surface area of the membrane
Answer: C
Q004: When observing onion cells in a hypotonic solution under a microscope,
what cellular change would you expect to see?
Options:
A. Plasmolysis and cell shrinkage
B. No visible change
C. Turgor pressure increase and cell swelling
D. Cell membrane rupture
Answer: C
Q005: In a laboratory demonstration of active transport, which molecule would
require the most ATP consumption for transport across a cell membrane?
Options:
A. Oxygen moving down its concentration gradient
B. Water through aquaporins
C. Sodium ions pumped against their gradient
D. Carbon dioxide diffusing freely
Answer: C
Q006: During a spectrophotometry lab measuring enzyme activity, you observe
that the rate of product formation decreases as substrate concentration increases.
What is the most likely explanation?
Options:
, 3
A. The enzyme is being saturated with substrate
B. The enzyme is experiencing substrate inhibition
C. The temperature is too low
D. The pH is optimal
Answer: B
Q007: In a respirometer experiment measuring cellular respiration in yeast, which
gas would be consumed and cause the drop in pressure observed?
Options:
A. Carbon dioxide
B. Nitrogen
C. Oxygen
D. Hydrogen
Answer: C
Q008: When testing the products of cellular respiration in germinating peas, which
reagent would you use to confirm the presence of carbon dioxide production?
Options:
A. Benedict's solution
B. Biuret reagent
C. Bromothymol blue
D. Iodine solution
Answer: C
Q009: In a photosynthesis experiment using spinach leaves and DCPIP, what color
change would indicate that photosynthesis is occurring?
Options:
A. Blue to clear
