Q.1
Potato slices were placed in sucrose solution. After half an hour, density of sucrose solution increased. Water potential of Potato tuber is ... ...[ JIPMER 1999 ]
  • a) Equal to solute potential of sucrose solution
  • b) Greater than solute potential of sucrose solution
  • c) Less than solute potential of sucrose solution
  • d) Half the concentration of sucrose solution
Q.2
For keeping stomata open, besides K ions the guard cells require a constant supply of ... ....
  • a) ABA
  • b) ATP
  • c) Organic acids
  • d) Protons
Q.3
Transpiration is dependent upon ... ... [ Odsiha 1995]
  • a) Difference of vapour pressure
  • b) Degree of stomatal opening
  • c) Availability of green light
  • d) Both a and b
Q.4
Passage of water across a selectively permeable membrane is ... ...
  • a) Active transport
  • b) Pinocytosis
  • c) Facilitated diffusion
  • d) Osmosis
Q.5
Root cap has no role in water absorption because ... ..... [ AIIMS 1990]
  • a) It has no direct connection with the vascular system
  • b) It has loosely arranged cells
  • c) It has no cells containing chloroplasts
  • d) It has no root hairs
Q.6
Movement of materials against concentration gradient is due to ... .. [ Bih PMT 2004]
  • a) Active transport
  • b) Passive transport
  • c) Diffusion
  • d) Osmosis
Q.7
Active K+ exchange mechanism for opening and closing of stomata was given by ... ... [ BHU 1997]
  • a) Darwin sup
  • b) Levitt
  • c) Scarth sup
  • d) Khorana
Q.8
Solution A has ψs = -30 bars and ψp = 5 bars. Solution B has ψs = -10 bars and ψp = 0 atm. The two are separated by semipermeable membrane. Flow of water will be ... ...[ KCET 2002]
  • a) B to A
  • b) A to B
  • c) Equal in both directions
  • d) No flow of water
Q.9
Cells absorb water through ... ... [ AMU 1999 ]
  • a) Osmosis only
  • b) Imbibition only
  • c) Both osmosis and imbibition
  • d) None of the above
Q.10
A wooden peg inserted in a rock causes its breaking during the rainy season. It is due to development of ... ...
  • a) Turgor pressure
  • b) Osmotic pressure
  • c) Matric potential
  • d) Plasmolysis
Q.11
Transpiration and root pressure cause water to rise in plants by : …[AIPMT 2015]
  • a) pushing and pulling it, respectively
  • b) pulling it upward
  • c) pulling and pushing it, respectively
  • d) pushing it upward
Q.12
Which of the following criteria does not pertain to facilitated transport ? …[NEET 2013]
  • a) Requirement of special membrane proteins
  • b) High selectivity
  • c) Transport saturation
  • d) Uphill transport
Q.13
A few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap ? …[NEET 2016]
  • a) Low refractive index
  • b) Absence of sugar
  • c) Acidic
  • d) Alkaline
Q.14
The water potential of pure water is….[NEET- 2017]
  • a) Zero
  • b) Less than zero
  • c) More than zero but less than one
  • d) More than one
Q.15
Root pressure develops due to : [ ReAIPMT 2015]
  • a) Increase in transpiration
  • b) Active absorption
  • c) Low osmotic potential in soil
  • d) Passive absorption
Q.16
Roots play insignificant role in absorption of water in : [ ReAIPMT 2015]
  • a) Wheat
  • b) Sunflower
  • c) Pistia
  • d) Pea
Q.17
A column of water within xylem vessels of tall trees does not break under its weight because of : [ ReAIPMT 2015]
  • a) Positive root pressure
  • b) Dissolved sugars in water
  • c) Tensile strength of water
  • d) Lignification of xylem vessels
Q.18
Which of the following elements is responsible for maintaining turgor in cells ? [NEET 2018]
  • a) Magnesium
  • b) Sodium
  • c) Potassium
  • d) Calcium
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