41. The phenomenon related to active water absorption is
A. Transpiration
B. Root pressure
C. Osmotic pressure
D. Translocation
Answer : Option B
42. Root pressure can be demonstrated by means of
43. Root pressure theory of ascent of sap is unacceptable because
A. Water can ascend without root or root pressure
B. Root pressure cannot explain ascent of sap beyond 10 metres.
C. Root pressure is more during early morning than afternoon.
D. Root pressur does not occur in spring.
Answer : Option A
44. Transpiration cohesion theory explains that the upwards pull of water is transmitted from top to bottom by cohesion of molecules caused by
A. Hydrophilic cell walls
B. Hydrogen bonds
C. Oxygen bonds
D. Surface tension
Answer : Option B
45. Root pressure is unable to explain the ascent of sap because it is not found in
46. Ascent of sap is
A. Upward movement of water in the plant
B. Downward movement of organic nutrients
C. Upward and downward movement of water in the plant
D. Redistribution of inorganic substances in the plant
Answer : Option D
47. In xylem, the ascent of sap takes place in
A. Tracheids with associated xylem parenchyma
B. Xylem parenchyma
C. Walls of tracheary elements
D. Lumen of tracheary elements
Answer : Option B
48. Swelling of wooden frames during rains is caused by
49. Dry seeds when placed in waeter swell up due to
50. A cell is plasmolysed after being kept in hypertonic solution. What will be present between cell wal and plasmalemma ?
A. Isotonic solution
B. Hypertonic solution
C. Air
D. Hypotonic solution
Answer : Option D