MCQ on Respiration in plant

Q1: Which organelle in plant cells is primarily responsible for cellular respiration?

(A) Chloroplast

(B) Mitochondrion

(C) Vacuole

(D) Nucleus

Answer: (B) Mitochondrion

Explanation: Mitochondria are the main sites of cellular respiration in plant cells, where ATP is produced.

Q2: During respiration, what is the primary substrate used by plants to generate energy?

(A) Oxygen

(B) Carbon dioxide

(C) Glucose

(D) Water

Answer: (C) Glucose

Explanation: Glucose is the primary substrate used by plants in cellular respiration to produce energy.

Q3: Which of the following is a product of the glycolysis stage of respiration in plants?

(A) Carbon dioxide

(B) Oxygen

(C) Pyruvate

(D) Water

Answer: (C) Pyruvate

Explanation: Glycolysis results in the formation of pyruvate as one of its products.

Q4: In plant respiration, where does the citric acid (Krebs) cycle occur?

(A) Cytosol

(B) Chloroplast

(C) Mitochondrion

(D) Vacuole

Answer: (C) Mitochondrion

Explanation: The citric acid cycle occurs within the mitochondria of plant cells.

Q5: Which stage of respiration in plants involves the bulk of ATP production?

(A) Glycolysis

(B) Krebs cycle

(C) Electron transport chain

(D) Fermentation

Answer: (C) Electron transport chain

Explanation: The electron transport chain is where the majority of ATP is produced during respiration.

Q6: In plant cells, what gas is the final electron acceptor in the electron transport chain?

(A) Carbon dioxide

(B) Hydrogen

(C) Oxygen

(D) Nitrogen

Answer: (C) Oxygen

Explanation: Oxygen serves as the final electron acceptor in the electron transport chain, allowing the formation of water.

Q7: Which process occurs when oxygen is scarce during plant respiration?

(A) Photosynthesis

(B) Fermentation

(C) Glycolysis

‘(D) Krebs cycle

Answer: (B) Fermentation

Explanation: When oxygen is scarce, plant cells may undergo fermentation to generate ATP.

Q8: What is the primary function of plant respiration?

(A) Producing glucose

(B) Removing excess oxygen

(C) Providing energy for cellular processes

(D) Synthesizing proteins

Answer: (C) Providing energy for cellular processes

Explanation: The primary purpose of plant respiration is to produce energy (in the form of ATP) for various cellular functions.

Q9: Which molecule is the energy currency in plant cells, produced during respiration?

(A) DNA

(B) RNA

(C) ATP

(D) Glucose

Answer: (C) ATP

Explanation: ATP (Adenosine Triphosphate) is the energy currency in plant cells produced during respiration.

Q10: What are the end products of plant respiration when oxygen is available?

(A) Carbon dioxide and water

(B) Oxygen and glucose

(C) Glucose and water

(D) Carbon dioxide and glucose

Answer: (A) Carbon dioxide and water

Explanation: In the presence of oxygen, plant respiration produces carbon dioxide and water as end products.

Q11: Where does glycolysis take place in plant cells?

(A) Mitochondrion

(B) Chloroplast

(C) Cytosol

(D) Nucleus

Answer: (C) Cytosol

Explanation: Glycolysis occurs in the cytosol (cytoplasm) of plant cells.

Q12: What is the primary source of glucose for plant respiration?

(A) Oxygen

(B) Photosynthesis

(C) Carbon dioxide

(D) Water

Answer: (B) Photosynthesis

Explanation: Photosynthesis is the process that produces glucose, which is then used in plant respiration.

Q13: In plant respiration, what is the role of the electron transport chain?

(A) Production of glucose

(B) Formation of pyruvate

(C) Synthesis of ATP

(D) Conversion of water to oxygen

Answer: (C) Synthesis of ATP

Explanation: The electron transport chain is responsible for the synthesis of ATP during plant respiration.

Q14: What type of respiration takes place in the absence of oxygen in plant cells?

(A) Anaerobic respiration

(B) Aerobic respiration

(C) Photosynthesis

(D) Oxidative phosphorylation

Answer: (A) Anaerobic respiration

Explanation: Anaerobic respiration occurs when oxygen is absent in plant cells.

Q15: What is the initial compound in the citric acid (Krebs) cycle during plant respiration?

(A) Oxalo-succinic acid

(B) Oxaloacetic acid

(C) Citric acid

(D) Cis-aconitic acid

Answer: (C) Citric acid

Explanation: The first compound in the citric acid cycle is citric acid.

Q16: Which organelle is involved in photosynthesis rather than respiration in plant cells?

(A) Mitochondrion

(B) Chloroplast

(C) Peroxisome

(D) Nucleus

Answer: (B) Chloroplast

Explanation: Chloroplasts are primarily responsible for photosynthesis, not respiration, in plant cells.

Q17: Who discovered glycolysis?

(A) Gustav Embden

(B) Otto Warburg

(C) Richard J. Roberts

(D) Barbara McClintock

Answer: (A) Gustav Embden

Explanation: Glycolysis was discovered by Gustav Embden.

Q18: Which type of respiration is catabolic and exergonic?

(A) Anabolic + exergonic

(B) Catabolic + exergonic

(C) Catabolic + endergonic

(D) Anabolic + endergonic

Answer: (B) Catabolic + exergonic

Explanation: Catabolic respiration releases energy, making it exergonic.

Q19: Why is a different enzyme involved in each step of glycolysis?

(A) Each step occurs in a different subcellular location.

(B) Each step occurs in a different cell.

(C) Each step involves a different chemical reaction.

(D) Each step involves a different change in potential energy.

Answer: (C) Each step involves a different chemical reaction.

Explanation: Different enzymes are involved in each step of glycolysis because each step represents a distinct chemical reaction.

Q20: Which of the following is not included in glycolysis?

(A) Substrate level phosphorylation occurs.

(B) The end products are CO2 and H2O.

(C) ATP is formed.

(D) ATP is used.

Answer: (B) The end products are CO2 and H2O.

Explanation: The end products of glycolysis are not CO2 and H2O, but rather pyruvate and some ATP.