ICSE Class 10

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

Objective

1. 1.
   The loss of water through a cut stem or injured part of a plant is known as:

   1. A. Transpiration
   2. B. Bleeding
   [1]
2. 2.
   What is the biological term for the movement of molecules of a substance from their higher concentration to lower concentration when they are in direct contact?

   1. A. Osmosis
   2. B. Diffusion
   3. C. Active transport
   4. D. Imbibition
   [1]
3. 3.
   Xylem

   1. A. Centre of the vascular bundle.
   2. B. Outer side of the vascular bundle.
   3. C. On the margins of leaves
   4. D. On the margins of roots.
   [1]
4. 4.
   Which type of solution causes water to leave a plant cell, resulting in the cell shrinking?

   1. A. Isotonic solution
   2. B. Hypotonic solution
   3. C. Hypertonic solution
   4. D. Distilled water
   [1]
5. 5.
   Which tissue is responsible for transporting manufactured starch from the leaves to all parts of the plant?

   1. A. Xylem
   2. B. Phloem
   3. C. Parenchyma
   4. D. Collenchyma
   [1]
6. 6.
   The tissue that conducts water.

   1. A. Phloem
   2. B. Xylem
   3. C. Companion cells
   4. D. Transfusion tissue
   [1]
7. 7.
   Which of the following statements about xylem is correct?

   1. A. Xylem is the food-conducting tissue in plants.
   2. B. Xylem is the water-conducting tissue in plants.
   3. C. Xylem is responsible for gas exchange in plants.
   4. D. Xylem transports only minerals, not water.
   [1]
8. 8.
   Active transport

   1. A. Passage of water from its lower to higher concentration through a cell membrane without any expenditure of energy.
   2. B. Passage of ions from its lower to higher concentration through a cell membrane without any expenditure of energy.
   3. C. Passage of water from its lower to higher concentration through a cell membrane using energy from the cell.
   4. D. Passage of ions from its lower to higher concentration through a cell membrane using energy from the cell.
   [1]
9. 9.
   _________ is the pressure exerted by all contents on the cell wall.

   1. a. Osmotic pressure
   2. b. Turgor pressure
   3. c. Wall pressure
   4. d. All of the above
   [1]
10. 10.
    Osmosis and diffusion are the same except that in osmosis there is

    1. A. a freely permeable membrane
    2. B. a cell wall in between
    3. C. a selectively permeable membrane in between
    4. D. an endless inflow of water into a cell
    [1]
11. 11.
    The leaves get wilted and droop down if _________

    1. a. Phloem is removed
    2. b. Cambium is removed
    3. c. Xylem is removed
    4. d. Both a and b
    [1]
12. 12.
    _________ occurs through semi-permeable membrane.

    1. a. Osmosis
    2. b. Diffusion
    3. c. Imbibition
    4. d. Transportation
    [1]
13. 13.
    Which term describes the ability of a solution to change the shape or tone of cells by altering their internal water volume?

    1. A. Osmolarity
    2. B. Tonicity
    3. C. Diffusion
    4. D. Permeability
    [1]
14. 14.
    Why do raisins swell up when placed in water, but grapes do not shrink when placed in a saturated sugar solution?

    1. A. Raisins swell due to osmosis and imbibition, while grapes have an impermeable skin preventing exosmosis in sugar solution.
    2. B. Raisins absorb water actively, while grapes shrink only in salt solutions due to osmotic pressure differences.
    3. C. Raisins swell because their cell walls break in water, while grapes remain unchanged due to their thicker skin.
    4. D. Raisins swell due to capillary action, while grapes do not shrink because sugar molecules are too large to exit their cells.
    [1]
15. 15.
    What is the exudation of watery sap from an injured part of a plant called?

    1. A. Guttation
    2. B. Bleeding
    3. C. Transpiration
    4. D. Excretion
    [1]
16. 16.
    What would happen if a rubber sheet or muslin cloth were used instead of cellophane in the osmosis experiment?

    1. A. No change in sugar solution level with rubber sheet; sugar solution flows to common level with muslin cloth.
    2. B. Sugar solution level rises with rubber sheet; no change with muslin cloth due to impermeability.
    3. C. Both rubber sheet and muslin cloth allow osmosis, causing sugar solution level to rise equally.
    4. D. Rubber sheet allows water to pass but blocks sugar; muslin cloth blocks both water and sugar.
    [1]
17. 17.
    How do turgor changes in guard cells control the opening and closing of stomata?

    1. A. Guard cells open stomata when flaccid due to low osmotic pressure and close when turgid.
    2. B. Guard cells become turgid due to glucose synthesis during photosynthesis, arching outward to open stomata, and become flaccid to close them.
    3. C. Stomata open when guard cells lose water by evaporation and close when they absorb water from adjacent cells.
    4. D. Guard cells control stomatal movement by changing their shape due to temperature fluctuations, not turgor pressure.
    [1]
18. 18.
    Which example correctly describes osmosis in the human body and a green leaf?

    1. A. Human: water from blood to body fluid; Leaf: water from mesophyll to veins.
    2. B. Human: water from body fluid to blood; Leaf: water from veins to mesophyll cells.
    3. C. Human: active transport of salts; Leaf: diffusion of CO₂.
    4. D. Human: plasmolysis in red blood cells; Leaf: transpiration pull.
    [1]
19. 19.
    Under what conditions does urine become hypotonic or hypertonic?

    1. A. Hypotonic when water intake is low; hypertonic when water intake is high
    2. B. Hypotonic when water intake is high; hypertonic when body water is low
    3. C. Hypotonic when salts are reabsorbed; hypertonic when glucose is reabsorbed
    4. D. Hypotonic when body is dehydrated; hypertonic when body is overhydrated
    [1]
20. 20.
    Concentration of mineral nutrient elements is higher inside the root-hairs than in the surrounding soil. How do roots take them in from the soil?

    1. A. Through passive diffusion, where minerals move from higher to lower concentration without energy.
    2. B. By active transport, using energy from ATP to move minerals against the concentration gradient.
    3. C. Via osmosis, where water carries dissolved minerals into the root-hairs.
    4. D. Through facilitated diffusion, where minerals move freely across the membrane without proteins.
    [1]