ICSE Class 10

General instructions: Answer all questions. Marks are shown in brackets [ ].

Objective

1. 1.
   What is the purpose of the reservoir in Ganong’s potometer?

   1. A. To store excess water for the plant to absorb over long periods.
   2. B. To adjust the position of the air bubble in the capillary tube for repeated measurements.
   3. C. To directly measure the rate of transpiration from the plant leaves.
   4. D. To provide oxygen to the plant roots submerged in the potometer.
   [1]
2. 2.
   Where are guard cells exactly located in a plant?

   1. A. In stomata.
   2. B. Along the leaf veins.
   3. C. Inside the mesophyll cells.
   4. D. On the surface of roots.
   [1]
3. 3.
   Lenticels

   1. A. They are present on the surface of leaves and stem.
   2. B. They are present on the surface of newly formed woody stem.
   3. C. They are present on the surface of older leaves and old woody stem.
   4. D. They are present on the surface of hard, old woody stem.
   [1]
4. 4.
   Where are guard cells located, and what is their primary function?

   1. A. Around the stomata in the leaf epidermis; control stomatal opening and closing.
   2. B. In the roots; absorption of minerals.
   3. C. In the stem; transport of water.
   4. D. In the flowers; pollen production.
   [1]
5. 5.
   Cuticle on leaves:

   1. A. Prevents photosynthesis.
   2. B. Reduces transpiration.
   3. C. Protects leaves from grazing animals.
   4. D. Gives colour to leaves.
   [1]
6. 6.
   Determine whether the following statement is true or false: Moist cobalt chloride paper is blue in colour.

   1. A. True
   2. B. False, dry cobalt chloride paper is blue
   3. C. False, it is always pink
   4. D. False, it is colorless when moist
   [1]
7. 7.
   Leaf modification in cacti to check transpiration.

   1. A. Thorns
   2. B. Phylloclade
   3. C. Prickles
   4. D. Spines
   [1]
8. 8.
   In a weighing experiment using a test-tube, we will ... to prevent evaporation.

   1. A. Cover test tube with paper
   2. B. Pouring oil on the surface
   3. C. Cover it with polythene bag
   4. D. Keep it in air- tight container
   [1]
9. 9.
   Assertion (A): A thick cuticle reduces transpiration by acting as a barrier. Reason (R): Desert plants have large, thin leaves for transpiration. Which of the following is correct?

   1. A. (A) is true and (R) is false.
   2. B. (A) is false and (R) is true.
   3. C. Both (A) and (R) are true and (R) explains (A).
   4. D. Both (A) and (R) are false.
   [1]
10. 10.
    How do folded leaves affect the rate of transpiration in a plant?

    1. A. Increases transpiration
    2. B. Reduces transpiration
    3. C. Has no effect on transpiration
    4. D. Stops transpiration completely
    [1]
11. 11.
    Which of the following accurately states the location and function of guard cells in a plant?

    1. A. Found in the epidermis of leaves around stomata; controls stomatal opening and closing.
    2. B. Located in the root tip; protects the growing region of the root.
    3. C. Present in the phloem; regulates transport of sugars.
    4. D. Inside the chloroplast; initiates the light-dependent reactions.
    [1]
12. 12.
    Glomerular filtrate contains

    1. a. blood with proteins but without cells
    2. b. plasma without sugars
    3. c. blood without urea
    4. d. blood plasma without blood cells and proteins
    [1]
13. 13.
    Why does a well-watered potted plant show wilting of leaves on a hot sunny day?

    1. A. The roots absorb too much water, causing leaf cells to burst.
    2. B. The rate of transpiration exceeds the rate of water absorption by roots.
    3. C. The plant undergoes dormancy due to excessive heat.
    4. D. The leaves lose chlorophyll due to intense sunlight.
    [1]
14. 14.
    With increase in atmospheric pressure, the rate of transpiration will:

    1. A. increase
    2. B. decrease
    3. C. remain steady
    4. D. slowly increase
    [1]
15. 15.
    Which of the following correctly describes the exact location and primary function of stomata in a plant?

    1. A. Present in the epidermis of leaves; helps in exchange of gases and transpiration.
    2. B. Found in the root hairs; aids in absorption of water and minerals.
    3. C. Located in the stem cortex; facilitates transport of nutrients.
    4. D. Inside the chloroplast; traps sunlight for photosynthesis.
    [1]
16. 16.
    Which of the following best explains why the leaves of certain plants roll up on a bright sunny day?

    1. A. To increase the rate of photosynthesis by exposing more chlorophyll.
    2. B. To reduce the exposed surface area and minimize water loss through transpiration.
    3. C. To protect the leaves from excessive sunlight damaging the cells.
    4. D. To trap moisture inside the leaves for better absorption.
    [1]
17. 17.
    What are scotoactive stomata, and which of the following is an example?

    1. A. Stomata that open only in daylight, e.g., maize
    2. B. Stomata that close during daytime but open at night, e.g., opuntia
    3. C. Stomata that remain closed at all times, e.g., cactus
    4. D. Stomata that open only in humid conditions, e.g., pine
    [1]
18. 18.
    There is a general belief that forests tend to bring more frequent rains. Which of the following provides the most accurate scientific explanation for this phenomenon?

    1. A. Forests release large amounts of water vapor through transpiration, increasing humidity and leading to cloud formation and precipitation.
    2. B. Forests absorb all sunlight, reducing evaporation from the ground and directly causing rainfall.
    3. C. Forests produce oxygen that chemically reacts with atmospheric gases to form rain clouds.
    4. D. Forests block wind movement, forcing moisture-laden air to rise and cool, but this has no direct link to rainfall frequency.
    [1]
19. 19.
    Balsam plants wilt during midday even if the soil is well-watered. Which of the following best explains this phenomenon?

    1. A. The rate of absorption exceeds the rate of transpiration
    2. B. The rate of transpiration exceeds the rate of absorption
    3. C. The soil water is insufficient for absorption
    4. D. The roots are damaged and cannot absorb water
    [1]
20. 20.
    Which of the following correctly differentiates between stoma and stroma?

    1. A. Stoma is the fluid matrix in chloroplasts; stroma is the opening between guard cells.
    2. B. Stoma is the small opening between guard cells; stroma is the ground substance of chloroplast.
    3. C. Stoma is involved in photosynthesis; stroma is involved in respiration.
    4. D. Stoma is found in roots; stroma is found in leaves.
    [1]