Free Bioenergetics MCQs with Answers
1,378 Bioenergetics MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Cellular respiration explains how cells release energy from glucose through glycolysis, the link reaction, Krebs cycle and electron transport chain. It includes ATP production, substrate-level and oxidative phosphorylation, aerobic versus anaerobic respiration, and the roles of mitochondria, oxygen and fermentation in energy transfer.
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- A. Carbon tetrachloride
- B. Alcohol
- C. Organic solvents
- D. Water
Explanation: Chlorophyll is a lipid-soluble pigment, so it dissolves in alcohol and other organic solvents but is insoluble in water.
Correct answer: Water- A. Algae
- B. Fungi
- C. Bacteria
- D. Spirogyra
Explanation: T.W. Engelmann obtained the first action spectrum using the filamentous green alga Spirogyra and aerobic bacteria that gathered near…
Correct answer: Spirogyra- A. T.W.Englemam
- B. Malleus
- C. T.W.Inws
- D. W.Stapes
Explanation: The first action spectrum was obtained by Theodor Wilhelm Engelmann, who used algal filaments and aerobic bacteria to relate oxygen…
Correct answer: T.W.Englemam- A. Orange
- B. Red
- C. Blue
- D. Green
Explanation: Green light is least absorbed by chlorophyll and is largely reflected, which is why most leaves look green.
Correct answer: Green- A. 20%
- B. 15%
- C. 10%
- D. 1%
Explanation: Only about 1% of the incident solar energy is ultimately captured and stored as chemical energy by photosynthesis in green plants.
Correct answer: 1%- A. 300 - 700 nm in wavelength
- B. 350 - 750 nm in wavelength
- C. 380 - 750 nm in wavelength
- D. 390 - 790 nm in wavelength.
Explanation: The photosynthetically useful part of visible light is commonly given as approximately 380 to 750 nm, covering the wavelengths absorbed by…
Correct answer: 380 - 750 nm in wavelength- A. 600
- B. 650
- C. 680
- D. 700
Explanation: Photosystem I has a reaction-centre chlorophyll a molecule called P700 because it absorbs maximally at about 700 nm.
Correct answer: 700- A. Bacteria
- B. Algae
- C. Protenema
- D. Cyanobacteria
Explanation: Van Niel developed his hypothesis from studies of photosynthetic bacteria, especially purple and green sulfur bacteria, and proposed that…
Correct answer: Bacteria- A. 0.02-0.03
- B. 0.03-0.04
- C. 0.04-0.05
- D. 0.05-0.06
Explanation: Atmospheric carbon dioxide is approximately 0.03% to 0.04% in the traditional textbook value used in many biology examinations.
Correct answer: 0.03-0.04- A. Neutral point
- B. Compensation point
- C. Parallel point
- D. Competitive point
Explanation: At the compensation point, the rate of carbon dioxide uptake and oxygen release in photosynthesis equals the rate of respiratory gas…
Correct answer: Compensation point- A. 1 molecule
- B. 6 molecules
- C. 3 molecules
- D. 0 molecule
Explanation: The simplified photosynthesis equation can be written as 6CO2 + 6H2O -> C6H12O6 + 6O2, so water is used rather than produced and its net…
Correct answer: 0 molecule- A. 10%
- B. 20%
- C. 30%
- D. 40%
Explanation: About 10% of total photosynthesis is attributed to terrestrial plants, whereas aquatic plants, algae, and other aquatic photosynthetic…
Correct answer: 10%- A. Glycolysis
- B. Respiration
- C. Photosynthesis
- D. Kreb's cycle
Explanation: Photosynthesis is an energy-storing process because light energy is converted into chemical energy in glucose, whereas glycolysis…
Correct answer: Photosynthesis- A. Animals
- B. Plants
- C. Both of these
- D. None of these
Explanation: Carotenoids protect photosynthetic tissues by dissipating excess light energy and preventing photooxidative damage to chlorophyll; in…
Correct answer: Both of these- A. Plants
- B. Animals
- C. Omnivores
- D. Fungi
Explanation: Plants use chlorophyll to convert sunlight into chemical energy during photosynthesis, making them primary producers.
Correct answer: Plants- A. Bioenergetics
- B. Laws of thermodynamics
- C. Laws of thermo chemistry
- D. Laws of chemical energetic
Explanation: Bioenergetics studies energy transformations in living systems, and these transformations follow the first and second laws of…
Correct answer: Laws of thermodynamics- A. Leaves respire and utilize O2 and release CO2.
- B. Photosynthesis and respiration occur at same rate. So there is not net exchange of gases between atmosphere and plants.
- C. Rate of photosynthesis increases, so do the O2 production, with a net release of oxygen coupled with the uptake of CO2.
- D. Rate of respiration becomes more than rate of photosynthesis.
Explanation: The compensation point occurs when photosynthesis and respiration proceed at equal rates, so the oxygen taken up and released, and the…
Correct answer: Photosynthesis and respiration occur at same rate. So there is not net exchange of gases between atmosphere and plants.- A. Day time.
- B. Night time.
- C. Dawn & Dusk.
- D. Mid night.
Explanation: At dawn and dusk, light intensity is near the compensation point, so photosynthetic carbon dioxide uptake balances respiratory carbon…
Correct answer: Dawn & Dusk.- A. Organic
- B. Energy rich
- C. Energy poor
- D. Reduced
Explanation: Carbon dioxide and water are inorganic and energy-poor compounds; photosynthesis uses light energy to reduce them into the energy-rich…
Correct answer: Energy poor- A. AMP
- B. ADP
- C. ATP
- D. All of these
Explanation: ATP links catabolism and anabolism because energy released during catabolic reactions is stored in ATP and then supplied by ATP hydrolysis…
Correct answer: ATP