Biochemistry MCQs part 1

1. A drug which prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase is

• Aspirin
• Allopurinol
• Colchicine
• Probenecid

2. Which of the following is required for crystallization and storage of the hormone insulin?

• Mn⁺⁺
• Mg⁺⁺
• Ca⁺⁺
• Zn⁺⁺

Plant Hormones MCQs Part 4

1. The Greek root words meaning "plant" and "color" are the basis for the term

• auxin
• tropism
• nastic
• phytochrome

2. How do some plants seeds "know" when it is day and night, and perhaps when to germinate?

• They chemically count the circadian cycles
• All plant hormones are products of photosynthetic systems
• Photosynthetic rates provide direct evidence of sun-produced food
• Phytochromes cycle between red and far-red absorption and light levels can inhibit germination

3. Gravitropism in roots

• is positive when plant roots grow downward
• is due to statoliths in the root cap cells
• is due to amyloplasts
• All of the choices are true

4. Apical dominance in plants is due to which of the following plant hormones?

• ethylene
• gibberellin
• auxins
• cytokinins

5. Which of the following is/are true regarding gibberellins?

• there are about 70 chemically different gibberellins
• are growth promoters causing stem elongation
• these hormones can break seed and bud dormancy
• all of the choices are true

6. Cytokinins

• are plant hormones that promote cell division
• are used in combination with auxin to produce plants from undifferentiated callose tissue
• also work with oligosaccharins to effect tissue differentiation
• All of these are true regarding cytokinins

7. which of the plant hormones ripens fruit and control abscission

• Auxin
• Gibberellin
• Abscisic acid
• Ethylene

8. Hormone which induces amylase production in seeds

• Auxin
• Gibberellin
• Abscisic acid
• Ethylene

9. Hormone which affects stomatal response to water stress

• Auxin
• Gibberellin
• Abscisic acid
• Ethylene

10. Hormone which promotes cell division

• Gibberellin
• Abscisic acid
• Ethylene
• Cytokinin

Score =

Correct answers:

Plant Hormones MCQs Parts => 1.. 2.. 3.. 4..

Photosynthesis MCQs part 5

1. In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP?

• energy released as electrons flow through the electron transport system
• energy released from substrate-level phosphorylation
• energy released from ATP synthase pumping hydrogen ions against their concentration gradient
• energy released from movement of protons through ATP synthase

2. Energy released by the electron transport chain is used to pump H+ ions into which location?

• cytosol
• mitochondrial outer membrane
• mitochondrial inner membrane
• mitochondrial intermembrane space

3. During aerobic cellular respiration, a proton gradient in mitochondria is generated by ____ and used primarily for ____.

• the electron transport chain, ATP synthesis
• the electron transport chain, substrate-level phosphorylation
• glycolysis, production of H₂O
• fermentation, NAD⁺ reduction

4. The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is

• oxidation of glucose to CO₂ and water
• the thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers
• the final transfer of electrons to oxygen
• the difference in H⁺ concentrations on opposite sides of the inner mitochondrial membrane

5. Where is ATP synthase located in the mitochondrion?

• cytosol
• outer membrane
• electron transport chain
• inner membrane

6. In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of

• ATP, CO₂ and ethanol (ethyl alcohol)
• ATP, CO₂, and lactate
• ATP, NADH, and pyruvate
• ATP, pyruvate, and oxygen

7. You have a friend who lost 7 kg (about 15 pounds) of fat on a "low carb" diet. How did the fat leave her body?

• It was released as CO₂ and H₂O
• Chemical energy was converted to heat and then released
• It was converted to ATP, which weighs much less than fat
• It was broken down to amino acids and eliminated from the body

8. Organisms that can exist with light as an energy source and an inorganic form of carbon and other raw materials

• are called photoautotrophs
• do not exist in nature
• are called heterotrophs
• are best classified as decomposers

9. Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

• CO₂ and glucose
• H₂O and O₂
• ADP, Pi, and NADP⁺
• ATP and NADPH

10. What is the primary function of the light reactions of photosynthesis?

• to produce energy-rich glucose from carbon dioxide and water
• to produce ATP and NADPH
• to produce NADPH used in respiration
• to convert light energy to the chemical energy of PGAL

Score =

Correct answers:

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Photosynthesis MCQs Parts => 1.. 2.. 3.. 4.. 5.. 6..

Plant Hormones MCQs Part 3

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Plant Hormones MCQs Parts => 1.. 2.. 3.. 4..

Animal Biotechnology MCQs Part 7

1. Which of the following is an example of cell devoid of nuclear membrane and mitochondria ?

• Bacterial cell
• Sperm
• Protist
• Sponge cell

2. Animal cell differs from plant cells in possessing __________

• plastid
• golgi body
• vacuole
• centrosome

Plant Biotechnology MCQs part 5

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Out of correct.

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Plant Biotechnology MCQs Parts => 1.. 2.. 3.. 4.. 5.. 6.. 7.. 8.. 9..