Plant Physiology – Respiration & Germination Quiz - ICSE Class 9 Biology

Free practice quiz: Plant Physiology – Respiration & Germination (ICSE Class 9 Biology). 49 multiple-choice questions with answers and explanations. Play online, no sign-up needed.

This ICSE Class 9 Biology practice quiz has 49 multiple-choice questions on Plant Physiology – Respiration & Germination, and 49 of them come with an explanation. Try the 5 sample questions below (tap an option to check yourself), then play the full quiz online. No sign-up needed.

Sample questions

1. Which of the following processes in plants directly utilizes atmospheric oxygen as a reactant?

   1. Photosynthesis
   2. Transpiration
   3. Aerobic Respiration
   4. Nitrogen Fixation
   Show answer

   Answer: C. Aerobic Respiration

   Aerobic respiration is a metabolic process that occurs in the presence of oxygen, where glucose is broken down to produce ATP, carbon dioxide, and water. Photosynthesis consumes carbon dioxide and releases oxygen. Transpiration is the loss of water vapor from plants. Nitrogen fixation is the conversion of atmospheric nitrogen into ammonia.

2. When fats are respired, the respiratory quotient (RQ) is typically:

   1. Equal to 1
   2. Greater than 1
   3. Less than 1
   4. Zero
   Show answer

   Answer: C. Less than 1

   Fats are more reduced compounds than carbohydrates and require more oxygen for their complete oxidation. For example, the respiration of tripalmitin (a fat) yields an RQ of approximately 0.7. This means more oxygen is consumed than carbon dioxide is produced.

3. Which of the following describes the energy yield during anaerobic respiration compared to aerobic respiration?

   1. Anaerobic respiration yields more ATP.
   2. Anaerobic respiration yields less ATP.
   3. Both yield the same amount of ATP.
   4. ATP yield is negligible in both.
   Show answer

   Answer: B. Anaerobic respiration yields less ATP.

   Anaerobic respiration only involves glycolysis, producing a net of 2 ATP molecules. Aerobic respiration, including glycolysis, the Krebs cycle, and the electron transport chain, yields significantly more ATP (around 30-32).

4. In the context of respiration, the energy stored in glucose is released and captured in the form of:

   1. Heat energy
   2. Light energy
   3. Mechanical energy
   4. Chemical energy (ATP)
   Show answer

   Answer: D. Chemical energy (ATP)

   Cellular respiration breaks down glucose through a series of steps, releasing energy that is then used to synthesize ATP (adenosine triphosphate), the primary energy currency of the cell.

5. During the germination of a dicotyledonous seed, the cotyledons are typically:

   1. Consumed entirely before the plumule emerges
   2. The primary sites of photosynthesis immediately after emergence
   3. Degraded and absorbed by the embryo
   4. The first structures to emerge from the seed coat
   Show answer

   Answer: C. Degraded and absorbed by the embryo

   Cotyledons serve as storage organs for food reserves. Once the embryo begins to grow, these reserves are broken down and absorbed by the developing seedling.

More questions in this quiz

Answers and explanations are in the full quiz.

1. During anaerobic respiration in plant cells, what is the primary end product that accumulates in the absence of oxygen?
2. The process by which a seed embryo develops into a seedling is known as:
3. Which of the following is NOT an essential condition for seed germination?
4. What is the role of the testa (seed coat) during germination?
5. The initial growth of the radicle from the seed embryo signifies the onset of:
6. In plants, the breakdown of stored food reserves during germination is primarily achieved through the action of:
7. Which component of the seed is responsible for the synthesis of hydrolytic enzymes that mobilize stored food reserves during germination?
8. The respiratory quotient (RQ) is defined as the ratio of CO2 produced to O2 consumed. What is the typical RQ value for carbohydrates?
9. Which hormone is primarily involved in breaking seed dormancy and promoting germination?
10. The process of breaking down glucose into two molecules of pyruvic acid is called:
11. The mitochondria are often referred to as the 'powerhouses' of the cell because they are the primary site for:
12. Which of the following is a characteristic of epigeal germination?
13. In hypogeal germination, which part of the seedling elongates first to push the plumule upwards?
14. The oxygen produced during photosynthesis is released into the atmosphere as a byproduct. Respiration, on the other hand, consumes oxygen. This highlights:
15. Which of the following conditions would most likely inhibit seed germination?
16. The primary function of the scutellum in monocotyledonous seeds during germination is:
17. The electron transport chain, a key part of aerobic respiration, is located in the:
18. Vernalization is a process that requires:
19. The carbon atoms from glucose in the Krebs cycle are released as:
20. What is the primary site of respiration in eukaryotic plant cells, besides the cytoplasm?
21. Which of the following is a critical factor for seed viability, meaning the seed's ability to remain alive and germinate?
22. The formation of ethanol and CO2 during anaerobic respiration in plants is an example of:
23. Which of the following enzymes is crucial for breaking down starch into simpler sugars during germination?
24. If a seed is placed in an environment with sufficient water and oxygen, but at a temperature far below its optimum for germination, what is the most likely outcome?
25. The process of oxidative phosphorylation, which produces the majority of ATP during aerobic respiration, occurs on the:
26. Which of the following is a common factor that can induce or maintain seed dormancy?
27. Stratification is a technique used to break seed dormancy by:
28. Which stage of aerobic respiration directly involves the conversion of pyruvate into acetyl-CoA?
29. The term 'photoblastic' refers to seeds whose germination is:
30. Which molecule serves as the direct electron donor to the electron transport chain in aerobic respiration?
31. The 'respiratory burst' observed during seed germination refers to:
32. When a seed imbibes water, the initial process that occurs is called:
33. The Chemiosmotic Theory explains how ATP is synthesized during respiration. What powers this process?
34. Seed dormancy can be broken by scarification, which involves:
35. The net gain of ATP from glycolysis alone is:
36. Which of the following is characteristic of the anaerobic respiration of some plant tissues like yeast or germinating grains under low oxygen conditions?
37. The plumule of a germinating seed develops into the:
38. Oxygen is crucial for aerobic respiration because it acts as:
39. Which type of seed storage reserve provides the most energy per gram when respired?
40. The metabolic process where organic compounds are broken down to release energy is called:
41. A seed that requires a period of moist chilling to break dormancy is said to require:
42. The respiratory process that occurs in the absence of oxygen is termed:
43. Which of the following factors generally ensures the longest viability of stored seeds?
44. In aerobic respiration, the primary role of the Krebs cycle is to:

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