#6 Biology Class 12 Chapter 6 - Plant Water Relations MHTCET / NEET MCQ
6 Plant Water Relations
(1) In soil, water available for absorption by root is .......... .
(a) gravitational water
(b) capillary water
(c) hygroscopic water
(d) combined water
Answer-
(b) capillary water
(2) The most widely accepted theory for ascent of sap is .......... .
(a) capillarity theory
(b) root pressure theory
(c) diffusion
(d) transpiration pull theory
Answer-
(d) transpiration pull theory
(3) Water movement between the cells is due to .......... .
(a) T.P.
(b) W.P.
(c) D.P. D.
(d) incipient plasmolysis
Answer-
(c) D.P. D.
(4) In guard cells, when sugar is converted into starch, the stomatal pore .......... .
(a) closes almost completely
(b) opens partially
(c) opens fully
(d) remains unchanged
Answer-
(a) closes almost completely
(5) Surface tension is due to .......... .
(a) diffusion
(b) osmosis
(c) gravitational force
(d) cohesion
Answer-
(d) cohesion
(6) Which of the following type of solution has lower level of solutes than the solution?
(a) Isotonic
(b) Hypotonic
(c) Hypertonic
(d) Anisotonic
Answer-
(b) Hypotonic
(7) During rainy season wooden doors warp and become difficult to open or to close because of .......... .
(a) plasmolysis
(b) imbibition
(c) osmosis
(d) diffusion
Answer-
(b) imbibition
(8) Water absorption takes place through .......... .
(a) lateral root
(b) root cap
(c) root hair
(d) primary root
Answer-
(c) root hair
(9) Due to low atmospheric pressure the rate of transpiration will .......... .
(a) increase
(b) decrease rapidly
(c) decrease slowly
(d) remain unaffected
Answer-
(a) increase
(10) Osmosis is a property of .......... .
(a) solute
(b) solvent
(c) solution
(d) membrane
Answer-
(c) solution
(11) What is the reason behind various properties of water ?
(a) Physical state
(b) Hydrogen bonding
(c) Colour
(d) Fluidity
Answer-
(b) Hydrogen bonding
(12) Which special type of tissue is present in epiphytic roots ?
(a) Velamen
(b) Lenticel
(c) Aerenchyma
(d) Haustoria
Answer-
(a) Velamen
(13) In which zone of root we come across root hairs ?
(a) meristematic region
(b) zone of elongation
(c) zone of absorption
(d) maturation zone
Answer-
(c) zone of absorption
(14) In double layered cell wall of root hair, outer layer is of .......... .
(a) cellulose
(b) pectin
(c) cutin
(d) suberin
Answer-
(b) pectin
(15) What is rhizosphere ?
(a) Root ball formed by growth of roots
(b) Covering of root tip
(c) Microenvironment around root
(d) region of root hairs
Answer-
(c) Microenvironment around root
(16) A root hair is derived from .......... cell.
(a) epidermal
(b) cortical
(c) endodermal
(d) pericycle
Answer-
(a) epidermal
(17) When we keep raisins in water they swell up, due to .......... .
(a) exosmosis
(b) plasmolysis
(c) imbibition
(d) diffusion
Answer-
(c) imbibition
(18) This phenomenon is associated with exchange of gases .......... .
(a) osmosis
(b) diffusion
(c) imbibition
(d) plasmolysis
Answer-
(b) diffusion
(19) What is correct expression for diffusion pressure deficit (D.P. D.) ?
(a) D.P. D. = O.P. - S.P.
(b) D.P. D. = T.P. - O.P.
(c) D.P. D. = W.P. - T.P.
(d) D.P. D. = O.P. - T.P.
Answer-
(d) D.P. D. = O.P. – T.P.
(20) What is true for a turgid cell ?
(a) T.P. is zero
(b) T.P. = S.P.
(c) D.P. D. is zero
(d) W.P. = S.P.
Answer-
(c) D.P. D. is zero
(21) The particles which easily diffuse through cell membrane are .......... .
(a) lipid soluble
(b) water soluble
(c) hydrophilic
(d) lipophobic
Answer-
(a) lipid soluble
(22) Which proteins help in facilitated diffusion process ?
(a) cutin
(b) mucin
(c) aquaporins
(d) lipoproteins
Answer-
(c) aquaporins
(23) D.P. D. is now known as .......... .
(a) water potential
(b) solute potential
(c) pressure potential
(d) osmotic potential
Answer-
(a) water potential
(24) Water always flows from .......... .
(a) more negative water potential to less negative water potential
(b) high water potential area to low water potential area
(c) low water potential area to high water potential area
(d) negative water potential area to area of zero water potential
Answer-
(b) high water potential area to low water potential are
(25) Plasmolysed cell becoming turgid is process of .......... .
(a) replasmolysis
(b) incipient plasmolysis
(c) deplasmolysis
(d) exosmosis
Answer-
(c) deplasmolysis
(26) In a fully turgid cell .......... .
(a) T.P. = O.P.
(b) T.P. = S.P.
(c) O.P. = S.P.
(d) T.P. = 0 (zero)
Answer-
(a) T.P. = O.P.
(27) Casparian strip of endodermis has material .......... .
(a) pectin
(b) suberin
(c) cutin
(d) porin
Answer-
(b) suberin
(28) Water from pericycle is forced into xylem due to .......... .
(a) aquaporin
(b) plasmodesmata
(c) root pressure
(d) ion-channels
Answer-
(c) root pressure
(29) Water absorbed from root hair when passes through intercellular spaces and cell wall it is .......... pathway.
(a) apoplast
(b) symplast
(c) transmembrane
(d) plasmodesmata
Answer-
(a) apoplast
(30) In root system, secondary roots arise from .......... .
(a) cortical cells
(b) endodermis
(c) pericycle
(d) passage cell
Answer-
(c) pericycle
(31) Active absorption of water occurs during .......... .
(a) early morning
(b) daytime
(c) bright sunlight
(d) night time
Answer-
(d) night-time
(32) The value of root pressure is usually about .......... .
(a) +1 to +12 bars
(b) –1 to +1 bars
(c) +1 to +2 bars
(d) +1 to +21 bars
Answer-
(c) +1 to +2 bars
(33) The ascent of sap in plants takes place through .......... .
(a) xylem
(b) phloem
(c) parenchyma
(d) endodermis
Answer-
(a) xylem
(34) From the following, which water will show greatest water potential ( Y )
(a) pure water
(b) salt water
(c) sugar water
(d) salt + sugar + water
Answer-
(a) pure water
(35) Due to entry of water in a cell, the pressure potential .......... .
(a) increases
(b) decreases
(c) remains unaffected
(d) becomes zero
Answer-
(a) increases
(36) Which mineral element is not remobilized in plants ?
(a) P
(b) K
(c) S
(d) Ca
Answer-
(d) Ca
(37) Phloem sap analysis is done using isotope .......... .
(a) 16O
(b) 14C
(c) 15N
(d) 35S
Answer-
(b) 14C
(38) In plants, food is mainly translocated in form of .......... .
(a) starch
(b) glucose
(c) sucrose
(d) amino acids
Answer-
(c) sucrose
(39) Transport of food through phloem is .......... .
(a) unidirectional
(b) bidirectional
(c) three dimensional
(d) absent
Answer-
(b) bidirectional
(40) Guttation occurs through .......... .
(a) stomata
(b) lenticels
(c) hydathodes
(d) velamen
Answer-
(c) hydathodes
(41) Amount of cuticular transpiration is about .......... .
(a) 0.1 – 1%
(b) 8 – 10%
(c) 90 – 93%
(d) 2 – 8%
Answer-
(b) 8 – 10%
(42) Epistomatic leaf shows .......... .
(a) stomata on upper side
(b) stomata on lower side
(c) stomata on both surfaces
(d) absence of stomata
Answer-
(a) stomata on upper side
(43) Dumbbell shaped guard cells are found in .......... .
(a) most dicots
(b) grasses
(c) gymnosperms
(d) desert plants
Answer-
(b) grasses
(44) Stomatal transpiration occurs during night time in .......... .
(a) most dicots
(b) grasses
(c) gymnosperms
(d) desert plants
Answer-
(d) desert plants
(45) Reservoir of K+ ions is .......... .
(a) guard cells
(b) epidermal cells
(c) subsidiary cells
(d) mesophyll
Answer-
(c) subsidiary cells
(46) Guard cells are surrounded by .......... .
(a) epidermal hairs
(b) mesophyll cells
(c) accessory cells
(d) lenticels
Answer-
(c) accessory cells
(47) When guard cells close stomata at night which acid prevents uptake of K+ and Cl– ions ?
(a) Abscissic acid
(b) Pyruvic acid
(c) Malic acid
(d) Acetic acid
Answer-
(a) Abscissic acid
(48) Which type of injury is noticed in plants if there is excessive transpiration ?
(a) Burning
(b) Chlorosis
(c) Necrosis
(d) Wilting
Answer-
(d) Wilting
(49) Maximum transpiration occurs through .......... .
(a) cuticle
(b) lenticels
(c) stomata
(d) bark
Answer-
(c) stomata
(50) What will be the condition of guard cells during night-time ?
(a) Show increased turgor pressure
(b) Become flaccid
(c) Increase uptake of K+ and Cl– ions
(d) Starch converted to sugar
Answer-
(b) Become flaccid
(51) Cell A has water potential – 10 bars and cell B has – 5 bars, the movement of water will occur from .......... .
(a) A to B
(b) B to A
(c) No movement
(d) Either A to B or B to A
Answer-
(b) B to A
(52) When root system absorbs water, which is the first physical process concerned with this activity ?
(a) Osmosis
(b) Imbibition
(c) Facilitated diffusion
(d) DiffusionAnswer-
Answer-
(b) Imbibition
