Root pressure is due to (HAR-PMT, MP-PMT)

1.Root pressure is due to (HAR-PMT, MP-PMT)
(a) active absorption
(b) passive absorption
(c) increased transpiration
(d) increased photosynthesis
Answer: (d)

2.Root pressure theory was proposed by ________.
(a) Priestley
(b) Stocking
(c) Boehm
(d) Dixon
Answer: (a)

3.The maximum absorption of water by roots occurs in the (region) zone of (M.P. PMT 2001)
(a) root cap
(b) cell division
(c) cell elongation
(d) root hairs
Answer: (d)

4.Of the processes which occur in leaves, the one which may lower their temperature (cooling effect) is (DPMT 86)
(a) respiration
(b) Photosynthesis
(c) Transpiration
(d) hydrolysis
Answer: (c)

5.Water is absorbed from outside solution only when it is (AFMC)
(a) saturated
(b) isotonic
(c) hypertonic
(d) hypotonic
Answer: (d)

6.Stomata of a plant open due to (CBSE)
(a) influx of potassium ions
(b) Efflux of potassium ions
(c) Influx of hydrogen ions
(d) Influx of calcium ions
Answer: (a)

7.Stomata close in response to
(a) hot dry weather
(b) abscisic acid
(c) cytokinin
(d) both (a) and (b)
Answer: (d)

8.Cohesion-tension theory is related to ________.
(a) respiration
(b) ascent of sap
(c) transpiration
(d) photosynthesis
Answer: (b)

9.The maximum loss of water in transpiration is from (Hariyana PMT 2005)
(a) Lenticels
(b) Cuticle
(c) Stomata
(d) Hydothodes
Answer: (c)

10.The following percentage of water absorbed by herbaceous plants is lost in transpiration (JIPMER 2002, MPPMT, CPMT)
(a) 80
(b) 60
(c) 99
(d) 40
Answer: (c)

11.Stomata open when the guard cells posses (CPMT)
(a) less K+
(b) more ABA
(c) More K+
(d) All of the above
Answer: (c)

12.Water lost through transpiration is
(a) pure water
(b) rich in organic solutes
(c) rich in dissolved salts
(d) all the above
Answer: (a)

13.The water available for plants in soil is ________.
(a) gravitational water
(b) hygroscopic water
(c) capillary water
(d) chemically bound water
Answer: (c)

14.About ______ percent of water absorbed by plants is lost by transpiration.
(a) 55
(b) 97
(c) 85
(d) 75
Answer: (b)

15.The conditions under which transpiration would be most rapid? (CPMT 81, AMU 87, BHU 77, DPMT 84)
(a) High humidity
(b) Excess of water in soil
(c) Low humidity, high temperature, guard cell are turgid (open) moist soil
(d) Low velocity of wind
Answer: (c)

16.Transpiration is helpful to plants in (AFMC, CPMT)
(a) Cooling
(b) loss of excess nutrients
(c) upward conduction/ascent of sap
(d) loss of excess water
Answer: (c)

17.Chlorophyllous cells fewer in number, unique in shape with inner walls thicker are (EAMCET)
(a) guard cells
(b) passage cells
(c) subsidiary cells
(d) bulliform cells
Answer: (a)

18.Water in plants is transported by which of the followings?
(a) Cambium
(b) phloem
(c) epidermis
(d) xylem
Answer: (d)

19.The most widely accepted theory of water translocation in plants is ______.
(a) Root pressure theory
(b) Capillary theory
(c) Cohesion theory
(d) Water pump theory
Answer: (c)

20.Which is produced during water stress that brings stomatal closure? (JIPMER, RPMT [2000], CBSE, AMU, MP-PMT, BHU)
(a) Ethylene
(b) Abscisic acid
(c) Ferulic acid
(d) Coumarin
Answer: (B)