Cohesive force of water is due to (RPMT, EAMCET)

1.Cohesive force of water is due to (RPMT, EAMCET)
(a) O-bonds
(b) OH-bonds
(c) S-bonds
(d) H-bonds
Answer: (d)

2.Each stoma is surrounded by (Har. PMT)
(a) passage cells
(b) guard cells
(c) parenchyma cells
(d) Lenticels
Answer: (b)

3.Transpiration increases by ________.
(a) high temperature
(b) high humidity
(c) wetness in soil
(d) large nuclei
Answer: (a)

4.Osmosis is intimately connected with ______ membrane.
(a) permeable
(b) semi-permeable
(c) selectively permeably
(d) impermeable
Answer: (b)

5.Maximum transpiration takes place from (RPMT 90)
(a) stem
(b) leaves
(c) roots
(d) flowers and fruits
Answer: (b)

6.Root pressure is maximum when (MPPMT, CPMT, MHT-CET)
(a) transpiration is high and absorption is low
(b) transpiration is very low and absorption is high
(c) transpiration is very high and absorption is high
(d) transpiration and absorption both are slow.
Answer: (b)

7.Epidermal cells containing chloroplasts are
(a) Hydathodes
(b) Accessory cells
(c) Stomata
(d) Guard cells
Answer: (d)

8.In guard cells, when sugar is converted into starch, what takes place to the stomatal pore?
(a) It closes completely.
(b) It opens fully.
(c) It opens partially
(d) It remains unchanged
Answer: (a)

9.Soil water is mainly absorbed by ______.
(a) root cap
(b) root meristem
(c) root hairs
(d) elongation
Answer: (c)

10.Stomatal opening is under the control of (KCET 1988, MANIPUR 2005)
(a) Epidermal cells
(b) Palisade cells
(c) Spongy parenchyma cells
(d) Guard cells
Answer: (d)

11.Dixon and Joly are associated with (CPMT 85)
(a) Light reaction and photosynthesis
(b) Anaerobic respiration
(c) Cohesion theory of ascent of sap
(d) Apical dominance
Answer: (c)

12.Which helps in opening of stomata?
(a) K+
(b) Ca2+
(c) H+
(d) Cl’
Answer: (a)

13.Water enters into root hairs from the soil on account of ________.
(a) turgor pressure
(b) osmotic pressure
(c) suction pressure
(d) root pressure
Answer: (b)

14.In a cell ruptures, on placing in a solution, the solution is said to be _____ with respect to cell sap
(a) hypotonic
(b) isotonic
(c) hypertonic
(d) pure water
Answer: (a)

15.Active K+ exchange mechanism for opening and closing of stomata was given by (RPMT 1985, BHU 1994 & 1997, RPMT 2002)
(a) Darwin
(b) Levitt
(c) Scarth
(d) Khorana
Answer: (b)

16.The most widely accepted theory for ascent of sap in trees is (AMUPMDC, JIPMER, AIMS, BHU, CBSE, EAMCET)
(a) Capillarity
(b) Role of atmospheric pressure
(c) Pulsating action of living cell
(d) Transpiration pull and cohesion theory of Dixon and Joly
Answer: (d)

17.Root pressure helps in ascent of sap by (BIHAR-PMT)
(a) pumping food in phloem
(b) pumping sap into xylem in roots
(c) pumping sap in stem for sending it to roots
(d) all of the above
Answer: (b)

18.In an angiosperm main conduction of water occurs through ________.
(a) tracheids
(b) sieve tubes
(c) vessels
(d) companion cells
Answer: (c)

19.Seeds swell when placed in water due to ________.
(a) Osmosis
(b) Imbibitions
(c) Hydrolysis
(d) Plasmolysis
Answer: (b)

20.Guard cells differ from epidermal cells in having (DPMT 1984, CPMT 1993)
(a) Mitochondria
(b) Vacuoles
(c) Cell Wall
(d) Chloroplasts
Answer: (d)