Std. 11th and Std. 12th Biology Question Papers. Appropriate for Medical Entrance Exams.
Questions |
Answers |
| 1. The hydrostatic pressure which is developed due to accumulation of water absorbed by roots is called (A) Turgor pressure (B) Wall pressure (C) Root pressure (D) Diffusion pressure |
Answer: (C) |
| 2. Root pressure is absent in (A) Herbaceous plants (B) Gymnosperms (C) Dicot plant (D) Trees |
Answer: (B) |
| 3. Root pressure is measured by (A) Barometer (B) Atmometer (C) Manometer (D) Auxanometer |
Answer: (C) |
| 4. Maximum root pressure is observed when (A) Transpiration and absorption are very low (B) Transpiration and absorption are very high (C) Transpiration is high and absorption is low (D) Transpiration is low an dabsorption is high |
Answer: (D) |
| 5. The existence of root pressure can be demonstrated by (A) Exudation or bleeding (B) Wilting (C) Transpiration (D) Bleeding |
Answer: (A) |
| 6. The most widely accepted theory for ascent of sap is (A) Root pressure theory (B) Pulsatory theory (C) Capillarity theory (D) Cohesion theory |
Answer: (D) |
| 7. The rate of absorption of water _____ with increase in salt concentration in the soil (A) Remains unchanged (B) Increases (C) Decreases (D) No effect |
Answer: (C) |
| 8. Which of the following physical forces are supposed to be responsible for ascent as sap? (A) Imbibition (B) Capillary force (C) Transpiration pull and cohesion (D) Root pressure |
Answer: (C) |
| 9. The ascent of sap takes place in (A) Xylem parenchyma (B) Walls of tracheary elements (C) Tracheids with associated xylem parenchyma (D) Lumen of tracheary elements |
Answer: (D) |
| 10. Upward movement of water in plants is (A) Transpiration (B) Ascent of sap (C) Exudation (D) Sucking |
Answer: (B) |
| 11. Lignin and cellulose present in xylem vessels shows affinity for water due to (A) Adhesive forces (B) Cohesive forces (C) Water potential d. Wall pressure |
Answer: (A) |
| 12. Turgidity of the cell is necessary for (A) Causes cell elongation (B) Causes opening and closing of stomata (C) Prevents wilting of leaves (D) All the above |
Answer: (D) |
| 13. In a plant cell, O.P. is equal to (A) D.P.D. – T.P. (B) D.P.D. + T.P. (C) T.P. – D.P.D (D) T.P. – D.P. |
Answer: (A) |
| 14. Cohesion – transpiration pull theory operates only in (A) Active water absorption (B) Passive water absorption (C) Conditions opposing transpiration (D) Conditions favouring transpiration |
Answer: (B) |
| 15. With rise in turgidity, wall pressure will (A) Increase (B) Decrease (C) Remain constant (D) Fluctuating |
Answer: (A) |
| 16. Pickes, jam, jellys has low risk of spoilage as they causes (A) Cuttation (B) Diffusion (C) Plasmolysis (D) Imbibition |
Answer: (C) |
| 17. Absorption of water from cut ends of stems disapproves the theory of (A) Capillarity (B) Cohesion-tension theory (C) Root pressure theory (D) Imbibitional pressure theory |
Answer: (C) |
| 18. The loss of water in the form of water droplets is called (A) Transpiration (B) Guttation (C) Evaporation (D) Bleeding |
Answer: (B) |
| 19. Transpiration occurs through (A) Stem (B) Roots (C) Leaves (D) All aerial parts of plant |
Answer: (D) |
| 20. Stomata open and close due to (A) Tugor pressure of guard cells (B) Root pressure (C) Positive pressure (D) Imbibitional pressure |
Answer: (A) |