O Level Biology: Respiration MCQs

Question 1

Yeast and sugar solution are kept at different temperatures. The rate of CO₂ production rises to 40 °C then falls because

Accepted Answer

respiration enzymes are denatured at high temperatures

Answer

yeast stops needing sugar

Answer

oxygen runs out at 40 °C

Answer

CO₂ dissolves faster

Question 2

Compared with anaerobic respiration, aerobic respiration releases

Accepted Answer

much more energy per glucose

Answer

no energy

Answer

the same energy

Answer

less energy

Question 3

The oxygen debt is repaid by

Accepted Answer

breaking down lactic acid in the liver using oxygen

Answer

making more lactic acid

Answer

storing lactic acid in bones

Answer

slowing breathing down

Question 4

During vigorous exercise, muscles respire anaerobically because

Accepted Answer

not enough oxygen reaches them

Answer

they have no glucose

Answer

they have too much oxygen

Answer

lactic acid is needed

Question 5

Which process is used in bread making?

Accepted Answer

Anaerobic respiration in yeast

Answer

Lactic acid fermentation in humans

Answer

Photosynthesis

Answer

Aerobic respiration in muscle

Question 6

After exercise, heart rate stays high to

Accepted Answer

carry lactic acid to the liver

Answer

make more lactic acid

Answer

cool the muscles

Answer

reduce breathing

Question 7

In which cells does respiration take place?

Accepted Answer

All living cells

Answer

Only plant cells

Answer

Only lung cells

Answer

Only muscle cells

Question 8

Which does NOT use energy from respiration?

Accepted Answer

Osmosis

Answer

Cell division

Answer

Active transport

Answer

Protein synthesis

Question 9

Which energy use is important in keeping mammals warm?

Accepted Answer

Maintaining a constant body temperature

Answer

Translocation

Answer

Osmosis

Answer

Photosynthesis

Question 10

What is the word equation for aerobic respiration?

Accepted Answer

glucose + oxygen → carbon dioxide + water

Answer

glucose → ethanol + carbon dioxide

Answer

glucose → lactic acid

Answer

carbon dioxide + water → glucose + oxygen

Question 11

Aerobic respiration takes place mainly in the

Accepted Answer

mitochondria

Answer

chloroplasts

Answer

nucleus

Answer

ribosomes

Question 12

Which process uses energy released by respiration?

Accepted Answer

Muscle contraction

Answer

Transpiration

Answer

Diffusion

Answer

Osmosis

Question 13

Which is the balanced equation for aerobic respiration?

Accepted Answer

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

Answer

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Answer

C₆H₁₂O₆ + O₂ → CO₂ + H₂O

Answer

C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂

Question 14

Which gas is a product of aerobic respiration?

Accepted Answer

Carbon dioxide

Answer

Hydrogen

Answer

Nitrogen

Answer

Oxygen

Question 15

Why does anaerobic respiration release less energy than aerobic respiration?

Accepted Answer

Glucose is only partly broken down

Answer

It uses more glucose

Answer

It needs more oxygen

Answer

It happens in mitochondria

Question 16

Respiration is best described as

Accepted Answer

chemical reactions in cells that release energy from nutrient molecules

Answer

the exchange of gases in the lungs

Answer

breathing in and out

Answer

making glucose using light

Question 17

The word equation for anaerobic respiration in human muscles is

Accepted Answer

glucose → lactic acid

Answer

glucose + oxygen → carbon dioxide + water

Answer

lactic acid → glucose

Answer

glucose → alcohol + carbon dioxide

Question 18

EPOC stands for

Accepted Answer

excess post-exercise oxygen consumption

Answer

energy produced on cell oxidation

Answer

enzymes producing oxygen and carbon

Answer

extra protein of cells

Question 19

Anaerobic respiration in yeast produces

Accepted Answer

alcohol and carbon dioxide

Answer

lactic acid

Answer

oxygen and water

Answer

glucose and oxygen

O Level Biology: Respiration MCQs — Biology

1. Yeast and sugar solution are kept at different temperatures. The rate of CO₂ production rises to 40 °C then falls because

2. Compared with anaerobic respiration, aerobic respiration releases

3. The oxygen debt is repaid by

4. During vigorous exercise, muscles respire anaerobically because

5. Which process is used in bread making?

6. After exercise, heart rate stays high to

7. In which cells does respiration take place?

8. Which does NOT use energy from respiration?

9. Which energy use is important in keeping mammals warm?

10. What is the word equation for aerobic respiration?

11. Aerobic respiration takes place mainly in the

12. Which process uses energy released by respiration?

13. Which is the balanced equation for aerobic respiration?

14. Which gas is a product of aerobic respiration?

15. Why does anaerobic respiration release less energy than aerobic respiration?

16. Respiration is best described as

17. The word equation for anaerobic respiration in human muscles is

18. EPOC stands for

19. Anaerobic respiration in yeast produces

More Biology chapters