Chemistry 9th Chap 8 : Topic 10 - Maryam Publications

Chemistry Chapter 8 : Topic 10

Respiration and Energy Storage

1 / 20

During intense physical exercise, muscle cells may switch from aerobic respiration to anaerobic respiration. Which statement best explains this change?

A) Carbon dioxide is required for anaerobic respiration to occur

B) Oxygen supply becomes insufficient, so cells partially break down glucose without oxygen

C) ATP production completely stops in muscles

D) Oxygen supply increases, so cells prefer anaerobic respiration

2 / 20

Which statement correctly compares aerobic and anaerobic respiration in terms of energy output?

A) Both produce equal amounts of energy per glucose molecule

B) Anaerobic respiration produces more energy than aerobic respiration

C) Neither process produces usable energy

D) Aerobic respiration produces significantly more energy than anaerobic respiration

3 / 20

Why is respiration considered an exothermic process?

A) It stores energy in glucose molecules

B) It absorbs heat from the surroundings

C) It releases energy during breakdown of glucose

D) It requires sunlight to proceed

4 / 20

Which best describes the role of ATP in biological systems?

A) It stores genetic information

B) It prevents anaerobic respiration

C) It is the immediate energy carrier for cellular processes

D) It acts as a long-term energy storage molecule

5 / 20

During anaerobic respiration in human muscles, which substance is produced?

A) Glucose

B) Oxygen

C) Lactic acid

D) Ethanol

6 / 20

Which organism commonly produces ethanol during anaerobic respiration?

A) Plants

B) Yeast

C) Humans

D) Fishes

7 / 20

Why does aerobic respiration release more energy than anaerobic respiration?

A) Because it produces lactic acid.

B) Because glucose is partially broken down.

C) Because glucose is completely oxidized into carbon dioxide and water.

D) Because no oxygen is used.

8 / 20

Which statement best explains why lipids are considered good energy reserves?

A) They store less energy than carbohydrates.

B) They are immediately used in all cellular reactions.

C) They contain more energy per gram than carbohydrates.

D) They dissolve easily in blood plasma.

9 / 20

What is the main advantage of storing energy as lipids instead of glucose?

A) Lipids store energy in a more compact and efficient form.

B) Lipids dissolve easily in water.

C) Lipids produce energy without respiration.

D) Lipids are heavier than glucose.

10 / 20

Which condition is most likely to trigger anaerobic respiration in humans?

A) High oxygen availability during sleep

B) Vigorous exercise causing oxygen shortage

C) Resting state with normal oxygen supply

D) Digestion of food in stomach

11 / 20

Which statement correctly describes energy release during respiration?

A) Energy is released gradually in usable form ATP.

B) Energy is destroyed during the process.

C) Energy is absorbed and stored in glucose.

D) Energy is only released as light.

12 / 20

Why does anaerobic respiration lead to fatigue in muscles?

A) Because glucose is fully oxidized.

B) Because oxygen increases excessively.

C) Due to accumulation of lactic acid.

D) Because ATP production increases too much.

13 / 20

Which equation best represents aerobic respiration?

A) Carbon dioxide + Water → Glucose + Oxygen

B) Glucose → Ethanol + Carbon dioxide

C) Glucose + Oxygen → Carbon dioxide + Water + Energy

D) Glucose → Lactic acid + Energy

14 / 20

Why is respiration essential for all living organisms?

A) It stores food permanently.

B) It prevents digestion.

C) It produces oxygen.

D) It provides energy required for life processes.

15 / 20

Which of the following is NOT a characteristic of lipids?

A) High energy content

B) Long-term energy storage

C) Insoluble in water

D) Immediate energy source like ATP.

16 / 20

What is the primary difference between respiration and combustion?

A) Both are non-energy releasing processes.

B) Respiration is a controlled release of energy in cells.

C) Respiration occurs only outside living cells.

D) Combustion releases energy in a controlled manner.

17 / 20

During starvation, the body mainly uses stored lipids for energy because:

A) Lipids replace ATP directly.

B) Lipids stop respiration completely.

C) Lipids are quickly converted into oxygen.

D) Lipids provide high energy yield when carbohydrates are low.

18 / 20

Which process directly produces ATP in cells?

A) Photosynthesis only

B) Respiration

C) Excretion

D) Digestion of food in stomach

19 / 20

Why is anaerobic respiration considered less efficient?

A) It produces no energy.

B) It releases much less ATP per glucose molecule.

C) It requires sunlight.

D) It breaks glucose completely.

20 / 20

Which statement best explains energy storage in lipids?

A) Lipids are used only in respiration of plants.

B) Lipids are stored in adipose tissue for long-term energy supply.

C) Lipids are stored in blood for immediate use.

D) Lipids are converted into ATP directly in blood plasma.

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