Keystone Test Biology: Cell Processes/Transport 2 — Questions and Answers
Question 1: A cell is placed in a solution where the solute concentration outside is higher than inside the cell. Which term describes this external solution?
- Hypotonic
- Isotonic
- Hypertonic (Correct answer)
- Neutral
Correct answer: Hypertonic
A hypertonic solution has a higher solute concentration than the cell's interior, causing water to leave the cell by osmosis.
Question 2: During cellular respiration, glucose is broken down in which order of stages?
- Krebs cycle → glycolysis → electron transport chain
- Glycolysis → Krebs cycle → electron transport chain (Correct answer)
- Electron transport chain → glycolysis → Krebs cycle
- Glycolysis → electron transport chain → Krebs cycle
Correct answer: Glycolysis → Krebs cycle → electron transport chain
Glycolysis occurs first in the cytoplasm, followed by the Krebs cycle and then the electron transport chain in the mitochondria.
Question 3: Which organelle is primarily responsible for producing ATP through aerobic respiration?
- Nucleus
- Ribosome
- Mitochondrion (Correct answer)
- Vacuole
Correct answer: Mitochondrion
The mitochondrion is the site of the Krebs cycle and electron transport chain, producing the majority of ATP in aerobic respiration.
Question 4: A red blood cell is placed in distilled water. What will happen to the cell?
- It will shrink due to plasmolysis
- It will remain unchanged
- It will swell and potentially burst (Correct answer)
- It will undergo active transport
Correct answer: It will swell and potentially burst
Distilled water is hypotonic relative to the cell, so water enters by osmosis causing the red blood cell to swell and potentially lyse.
Question 5: Which process moves substances across the cell membrane WITHOUT using energy, moving from high to low concentration?
- Active transport
- Endocytosis
- Passive diffusion (Correct answer)
- Sodium-potassium pump
Correct answer: Passive diffusion
Passive diffusion moves substances down their concentration gradient from high to low concentration without requiring cellular energy.
Question 6: What is the net ATP yield from one molecule of glucose during complete aerobic respiration?
- 2 ATP
- 4 ATP
- 36–38 ATP (Correct answer)
- 100 ATP
Correct answer: 36–38 ATP
Complete aerobic respiration of one glucose molecule produces approximately 36–38 ATP molecules through glycolysis, the Krebs cycle, and oxidative phosphorylation.
Question 7: Which molecule acts as the final electron acceptor in the electron transport chain during aerobic respiration?
- Carbon dioxide
- Water
- Oxygen (Correct answer)
- NADH
Correct answer: Oxygen
Oxygen accepts electrons at the end of the electron transport chain, combining with hydrogen ions to form water as a byproduct.
Keystone Test Biology: Cell Processes/Transport 2
A cell is placed in a solution where the solute concentration outside is higher than inside the cell.
Which term describes this external solution?