Q61. Pinus seed cannot germinate and established without fungal association. This is because:
(1) its embryo is immature.
(2) it has obligate association with mycorrhizae
(3) it has very hard seed coat.
(4) its seeds contain inhibitors that present germination.
Ans.2
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Q62. Stomatal movement is not affected by
(1) Temperature
(2) CO2 concentration
(3) Light
(4) O2 concentration
Ans.4
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Q63. Which of the following facilitates opening of stomatal aperture?
(1) Contraction of outer wall of guard cells
(2) Decrease in turgidity of guard cells
(3) Radial orientation of cellulose microfibrils in the cell wall of guard cells
(4) Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells
Ans.3
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Q64. The water potential of pure water is
(1) Zero
(2) Less than zero
(3) More than zero but less than one
(4) More than one
Ans.1
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Q65. 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?
(1) Acidic
(2) Alkaline
(3) Low refractive index
(4) Absence of sugar
Ans.2
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Q66. Water vapour comes out from the plant leaf through the stomatal opening. Through the same stomatal opening carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using one of following options
(1) One process occurs during day time, and the other at night
(2) Both processes cannot happen simultaneously
(3) Both processes can happen together because the diffusion coefficient of water and CO₂ is different
(4) The above processes happen only during night time
Ans.3
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Q67. Root pressure develops due to
(1) Increase in transpiration
(2) Active absorption
(3) Low osmotic potential in soil
(4) Passive absorption
Ans.2
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Q68. A column of water within xylem vessels of tall trees does not break under its weight because of
(1) Positive root pressure
(2) Dissolved sugar in water
(3) Tensile strength of water
(4) Lignification of xylem vessels
Ans.3
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Q69. Transpiration and root pressure cause water to rise in plants by
(1) Pushing and pulling it, respectively
(2) Pulling it upward
(3) Pulling and pushing it, respectively
(4) Pushing it upward
Ans.3
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Q70. In a ring girdled plant
(1) Neither root nor shoot will die
(2) The shoot dies first
(3) The root dies first
(4) The shoot and root die together
Ans.3
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Q71. Which one gives the most valid and recent explanation for stomatal movements?
(1) Guard cell photosynthesis
(2) Transpiration
(3) Potassium influx and efflux
(4) Starch hydrolysis
Ans.3
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Q72. Which of the following criteria does not pertain to facilitated transport?
(1) High selectivity
(2) Transport saturation
(3) Uphill transport
(4) Requirement of special membrane proteins
Ans.3
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Q73. Lenticels are involved in
(1) Gaseous exchange
(2) Food transport
(3) Photosynthesis
(4) Transpiration
Ans.1
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Q74. Guttation is the result of
(1) Osmosis
(2) Root pressure
(3) Diffusion
(4) Transpiration
Ans.2
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Q75. Which one of the following structures between two adjacent cells is an effective transport pathway?
(1) Plasmalemma
(2) Plasmodesmata
(3) Plastoquinones
(4) Endoplasmic reticulum
Ans.2
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