31. Scotoactive movement of stomata is that
A. Stomata open at night
B. Stomata open during day
C. Stomata close at night
D. Stomata open both during day and night
Answer : Option A
32. The most effective light for stomatal opening is_____________
33. During high wind velocity, the stomata
A. open more widely
B. Close down
C. Remian unaffected
D. Remain unaffected but lose more water due to mass action
Answer : Option B
34. Cobalt chloride is blue in dry state. In contact with moisture, it turns in to
35. The maximum absorption of water by roots occurs in the (region) zone of
36. The movement of water is along
A. Turgor gradient
B. DPD gradient
C. Diffusion gradient
D. Osmotic gradient
Answer : Option B
37. As absorbed water passes towards vascular cylinder, it must enter the cytoplasm of
A. Pericycle cells
B. Endodermal cells
C. Cortical cells
D. Xylem parenchyma
Answer : Option B
38. Water tightly held to soil particles is called
A. Bound water
B. Capillary water
C. Hygroscopic water
D. Runaway water
Answer : Option C
39. The phenomenon which forces water upward into tracheal elements of xylem in the root region is
A. Transpiration
B. Root pressure
C. Turgor pressure
D. Imbibation pressure
Answer : Option B
40. Force for passive water absorption develops in