Metabolism Cell Respiration and Photosynthesis Practice Questions
IB (International Baccalaureate) · IB Biology HL · 150 free MCQs with instant results and detailed explanations.
150
Total
48
Easy
71
Medium
31
Hard
Start Practicing Metabolism Cell Respiration and Photosynthesis
Take a timed quiz or customize your practice session
Sample Questions from Metabolism Cell Respiration and Photosynthesis
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
Which of the following processes occurs in the mitochondria of eukaryotic cells?
A.
Glycolysis
B.
Citric Acid Cycle
C.
Fermentation
D.
Light Reactions
Show Answer & Explanation
Correct Answer: B
The Citric Acid Cycle, also known as Krebs Cycle, takes place in the mitochondrial matrix. Glycolysis occurs in the cytoplasm, fermentation happens in the absence of oxygen, and light reactions occur in chloroplasts.
Q2
Easy
What is the primary role of NAD+ in cellular respiration?
A.
To provide energy directly
B.
To donate electrons
C.
To synthesize glucose
D.
To fix carbon dioxide
Show Answer & Explanation
Correct Answer: B
NAD+ acts as an electron carrier during cellular respiration. It accepts electrons during glycolysis and the citric acid cycle, becoming NADH, and plays a crucial role in the transport of electrons to the electron transport chain.
Q3
Easy
Which molecule is produced during the light-dependent reactions of photosynthesis?
A.
Glucose
B.
Oxygen
C.
ATP
D.
Both B and C
Show Answer & Explanation
Correct Answer: D
During the light-dependent reactions of photosynthesis, ATP and oxygen are produced. Water is split, releasing oxygen, and ATP is generated through photophosphorylation.
Q4
Medium
Which of the following statements correctly describes the role of NADH in cellular respiration?
A.
NADH donates electrons to the electron transport chain.
B.
NADH is produced only during glycolysis.
C.
NADH is converted back to NAD+ without producing ATP.
D.
NADH is used to synthesize glucose during photosynthesis.
Show Answer & Explanation
Correct Answer: A
NADH donates electrons to the electron transport chain, facilitating the production of ATP through oxidative phosphorylation.
Q5
Medium
In a certain plant, the rate of photosynthesis doubles when light intensity is increased from 200 to 400 µmol m-2 s-1. What is the effect of light intensity on the rate of photosynthesis called?
A.
Light saturation
B.
Photosynthetic efficiency
C.
Light limitation
D.
Photoinhibition
Show Answer & Explanation
Correct Answer: A
When the rate of photosynthesis doubles due to an increase in light intensity, it indicates that the plant is approaching light saturation, where further increases in light will not yield a proportional increase in photosynthesis.
Q6
Medium
What is the net gain of ATP molecules produced from one glucose molecule during glycolysis?
A.
2 ATP
B.
4 ATP
C.
1 ATP
D.
3 ATP
Show Answer & Explanation
Correct Answer: A
During glycolysis, 4 ATP are produced, but 2 ATP are used, resulting in a net gain of 2 ATP per glucose molecule.
Q7
Medium
Which of the following best explains why aerobic respiration produces more ATP than anaerobic respiration?
A.
Aerobic respiration involves the Krebs cycle and oxidative phosphorylation.
B.
Anaerobic respiration occurs in the cytoplasm only.
C.
Aerobic respiration uses glucose more efficiently.
D.
Anaerobic respiration does not use coenzymes.
Show Answer & Explanation
Correct Answer: A
Aerobic respiration includes the Krebs cycle and the electron transport chain which yield more ATP compared to the limited ATP produced during anaerobic respiration.
Q8
Hard
Which of the following statements correctly describes the role of oxygen in cellular respiration?
A.
Oxygen acts as the final electron acceptor in the electron transport chain.
B.
Oxygen is converted into glucose during glycolysis.
C.
Oxygen is required to directly produce ATP in the citric acid cycle.
D.
Oxygen is produced as a by-product of the Krebs cycle.
Show Answer & Explanation
Correct Answer: A
Oxygen is essential in cellular respiration as it serves as the final electron acceptor in the electron transport chain, allowing for the formation of water and the continuation of ATP production via oxidative phosphorylation.
Q9
Hard
In a controlled experiment, a scientist measures the rate of photosynthesis in two different plant species under identical light conditions. Species A has a higher rate of photosynthesis than Species B. Which of the following could explain this discrepancy?
A.
Species A has a higher chlorophyll concentration than Species B.
B.
Species A performs cellular respiration more quickly than Species B.
C.
Species B is adapted to low-light conditions.
D.
Species A has a lower leaf surface area than Species B.
Show Answer & Explanation
Correct Answer: A
A higher chlorophyll concentration in Species A means that it can absorb more light energy, which directly enhances the rate of photosynthesis compared to Species B, assuming all other factors are identical.
Q10
Hard
Which of the following statements accurately describes the role of NADH in cellular respiration?
A.
NADH is produced during glycolysis and the Krebs cycle, and it donates electrons to the electron transport chain.
B.
NADH is synthesized from glucose during photosynthesis and used directly for ATP synthesis.
C.
NADH is a byproduct of anaerobic respiration that inhibits the Krebs cycle.
D.
NADH is involved in the Calvin cycle to produce glucose from carbon dioxide.
Show Answer & Explanation
Correct Answer: A
NADH is an important electron carrier that is generated during glycolysis and the Krebs cycle. It donates electrons to the electron transport chain, where its oxidation contributes to ATP production.
Showing 10 of 150 questions. Start a quiz to practice all questions with scoring and timer.
Practice All 150 Questions →Other IB (International Baccalaureate) Subjects
Metabolism Cell Respiration and Photosynthesis — IB (International Baccalaureate) IB Biology HL Practice Questions Online
This page contains 150 practice MCQs for the chapter Metabolism Cell Respiration and Photosynthesis in IB (International Baccalaureate) IB Biology HL. The questions are organized by difficulty — 48 easy, 71 medium, 31 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit.