Below are the NEET MCQ questions on Class 11 Biology Chapter “Transport in Plants” based on the NCERT textbook. Solve the below free NEET mock test for a better understanding of the various topics. 100+ important MCQs (multiple choice questions) are given in this NEET question bank.
“Transport in Plants” is the 11th chapter in the unit “Plant Physiology” of class XI or class 11th Biology NCERT. Do note that NEET (which is conducted by NTA) is based on NCERT textbooks so they are a must-have. You can also download PDFs of NCERT textbooks.
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- Plant roots can receive minerals through several mechanisms, except for one. What mechanism does NOT move minerals into roots?
(a) Foliar feeding
(b) Active transport
(c) Proton (H+) pump
(d) Cation exchange
(a) Foliar feeding
- A botanist discovered a mutant plant that was incapable of producing materials that form casparian strips. This plant would be
(a) unable to transport water or solutes to the leaves.
(b) unable to use its sugar as a sugar sink.
(c) able to exert greater root pressure than the normal plant.
(d) unable to control amounts of water and solutes it absorbs.
(d) unable to control amounts of water and solutes it absorbs.
- If a cell A with D.P.D. 4 bars is connected to cells B, C, and D whose O.P. and T.P. are respectively 4 and 4, 10 and 5 and 7 and 3 bars, what would the flow of water look like
(a) A and D to B and C
(b) A to B, C and D
(c) B to A, C and D
(d) C to A, B and D
(c) B to A, C and D
- A leaf’s mesophyll tissue has a water potential of -10 bars, while its epidermis has a water potential of -8 bars, and the air outside has a water potential of -5 bars. How will the water move?
(a) air to the epidermis to mesophyll
(b) mesophyll to air to the epidermis
(c) mesophyll to the epidermis to air
(d) nowhere
(a) air to the epidermis to mesophyll
- What will happen to a plant cell if it is placed in pure water?
(a) expands until the osmotic potential or solute potential reaches that of water.
(b) becomes more turgid until the pressure potential of the cell reaches its osmotic potential.
(c) becomes more turgid until the osmotic potential reaches that of pure water.
(d) becomes less turgid until the osmotic potential reaches that of pure water.
(b) becomes more turgid until the pressure potential of the cell reaches its osmotic potential.
- Peeled potato is cut into halves and a cup-like cavity is made in its cut end. The potato piece is placed in a petri dish having ordinary water and some sugar crystals are placed in the potato cavity. What will happen to the sugar crystals after some time?
(a) be turned black
(b) move into the water in the petri dish
(c) form sugar solution
(d) remain unchanged
(c) form sugar solution
- An apple plant’s transpiration rate is measured on both leaf surfaces. Where will it be higher?
(a) lower surface
(b) upper surface
(c) none of the two surface
(d) All of these
(a) lower surface
- If two solutions have the same osmolarity, what are they said to be?
(a) hypotonic
(b) hypertonic
(c) isotonic
(d) None of these
(c) isotonic
- In plants, transpiration rate depends on?
(a) temperature and soil
(b) light and temperature
(c) wind, temperature and light
(d) light, temperature, atmospheric humidity and wind
(d) light, temperature, atmospheric humidity and wind
- When does wilting occur?
(a) rate of transpiration is higher than absorption.
(b) rate of absorption is higher than transpiration.
(c) there is excess root pressure.
(d) there is high relative humidity in the air.
(a) rate of transpiration is higher than absorption.
- Which is false?
(a) Diffusion is the movement of particles from low electrochemical potential to high electrochemical potential.
(b) Rate of diffusion is directly proportional to concentration.
(c) Rate of diffusion is inversely proportional to the distance
(d) Example of diffusion is the opening of a bottle of scent in one corner.
(a) Diffusion is the movement of particles from low electrochemical potential to high electrochemical potential.
- Guttation occurs through what?
(a) lenticels
(b) hydathodes
(c) periderm
(d) stomata
(b) hydathodes
- An apple plant’s transpiration rate is measured on both leaf surfaces. On which surface will it be higher on?
(a) lower surface
(b) upper surface
(c) None of the two surface
(d) Both (a) and (b)
(a) lower surface
- Movement of ions or molecules that move in the opposite direction of the prevailing electrochemical gradient is called?
(a) diffusion
(b) active transport
(c) pinocytosis
(d) Brownian movement
(b) active transport
- Which atmospheric factor acts as an anti-transpirant?
(a) SO2
(b) CO
(c) CO2
(d) All pollutant gases
(c) CO2
- Although water is lost in the form of vapour in both transpiration and evaporation, they differ. This is because
(a) Both transpiration and evaporation are similar but the rate of water loss differs
(b) Frequency of water loss is different in both of them
(c) Transpiration is a physical process and evaporation is a physiological process
(d) Transpiration is a physiological process and evaporation is a physical process
(d) Transpiration is a physiological process and evaporation is a physical process
- What does transpiration facilitate?
(a) Electrolyte balance
(b) Opening of stomata
(c) Absorption of water by roots
(d) Excretion of minerals
(c) Absorption of water by roots
- Which of the following helps in the absorption of water and mineral salts?
(a) Mycorrhiza
(b) Anabaena
(c) Nostoc
(d) None of these
(a) Mycorrhiza
- During sap ascent, ruptures and fractionations do not typically occur in the water column of vessels/tracheids because?
(a) lignified thick walls
(b) cohesion and adhesion
(c) weak gravitational pull
(d) transpiration pull
(b) cohesion and adhesion
- In vessels/tracheids, ruptures and fractionations rarely occur during an ascent of sap because of?
(a) Weak gravitational pull
(b) Transpiration pull
(c) Lignified thick walls
(d) Cohesion and adhesion
(d) Cohesion and adhesion
- When placed in what solution can a plasmolysed cell be deplasmolyzed?
(a) Isotonic solution
(b) Hypertonic solution
(c) Saturated solution
(d) Pure water or hypotonic solution
(d) Pure water or hypotonic solution
- What causes the doors to swell during the rainy season?
(a) Imbibition
(b) Absorption
(c) Diffusion
(d) Endosmosis
(a) Imbibition
- What is developed with the addition of solute in a cell?
(a) Turgor pressure
(b) Osmotic pressure
(c) Diffusion pressure
(d) Water potential
(b) Osmotic pressure
- When the cell becomes fully turgid, which of the following will be zero?
(a) Turgor pressure
(b) Wall pressure
(c) Suction pressure
(d) Osmotic pressure
(c) Suction pressure
- A mycorrhizal fungus provides plants with which of the following?
(a) Carbonate
(b) Phosphate
(c) Chloride
(d) Nitrate.
(b) Phosphate
- Why does the water logging of soil make it physiologically dry?
(a) this condition does not allow the capillary force to work
(b) this condition does not allow oxygen to enter the soil
(c) Both (a) and (b)
(d) None of the above
(b) this condition does not allow oxygen to enter the soil
- Volume of a cell increases if the external medium is?
(a) Hypotonic
(b) Hypertonic
(c) Isotonic
(d) None of these
(a) Hypotonic
- What is the principle behind potometers?
(a) osmotic pressure
(b) amount of water absorbed is equal to the amount transpired
(c) root pressure
(d) potential difference between the tip of the tube and that of the plant
(b) amount of water absorbed is equal to the amount transpired
- What explains the translocation of organic materials in plants?
(a) active transport
(b) transpiration pull
(c) inhibition theory
(d) mass flow hypothesis
(a) active transport
- Translocation of what is the main function of phloem?
(a) food
(b) water
(c) mineral
(d) air
(a) food
- Why do doors get swelled up in the rainy season?
(a) imbibition
(b) diffusion
(c) transpiration
(d) respiration
(a) imbibition
- Which of the following helps in the ascent of sap?
(a) Root pressure
(b) Transpiration
(c) Capillarity
(d) All of these
(d) All of these
- What is hydroponics?
(a) nutrient less culture
(b) waterless culture
(c) soilless culture
(d) none of these
(c) soilless culture
- What happens during Na+ – K+ pump?
(a) 3Na+ and 2K+ are transported
(b) 1Na+ and 2K+ are transported
(c) 3 Na+ and 3K+ are transported
(d) Depends on the requirement of the cell
(a) 3Na+ and 2K+ are transported
- Excessive loss of water causes wilting of leaves. How can this be prevented?
(a) Keeping the plant in bright light
(b) Spraying the plant with alcohol
(c) Applying vaseline on the leaf surface
(d) Adding high amounts of fertilizers to the soil
(c) Applying vaseline on the leaf surface
- Pure water and its solution have what water potential?
(a) 0 and 1
(b) 0 and 0
(c) 0 and more than one
(d) 0 and less than 1.
(d) 0 and less than 1.
- A carrier molecule is not required in which method of transport in the plasma membrane?
(a) Active transport
(b) Facilitated diffusion
(c) Simple diffusion
(d) Na+ – K+ pump
(c) Simple diffusion
- How does the seed absorb water to increase its volume?
(a) Osmosis
(b) Plasmolysis
(c) Imbibition
(d) Diffusion
(c) Imbibition
- Why does dough kept overnight in warm weather become soft and spongy?
(a) absorption of carbon dioxide from the atmosphere
(b) fermentation
(c) cohesion
(d) osmosis
(b) fermentation
- What causes the stomata of a plant open?
(a) influx of calcium ions
(b) influx of potassium ions
(c) efflux of potassium ions
(d) influx of hydrogen ions
(b) influx of potassium ions
- What plant has the least transpiration?
(a) Nerium
(b) Hydrilla
(c) Mango
(d) Guava
(a) Nerium
- What type of pressure develops when water moves through a semi-permeable membrane?
(a) O. P.
(b) S. P
(c) T. P.
(d) W. P
(a) O. P.
- If cell A with DPD 4 bars is connected to cells B, C, and D whose OP and TP are respectively 4 and 4, 10 and 5 and 7 and 3 bars, how will the flow of water be?
(a) A and D to B and C
(b) A to B, C and D
(c) B to A, C and D
(d) C to A, B and D
(c) B to A, C and D
- An aquatic plant is placed in a test tube containing distilled water and the tube is stoppered. The tube is left outdoors for 24 hours and the pH value of the water is then measured at regular intervals. What is the most likely outcome?
(a) The pH value is lowest just before sunrise
(b) The pH value is highest just before sunrise
(c) The pH value is lowest at noon
(d) The pH value is lowest just before sunset.
(a) The pH value is lowest just before sunrise
- What is the difference between active and passive transports across cell membranes?
(a) passive transport is nonselective
(b) passive transport is along the concentration gradient while active transport is due to metabolic energy
(c) active transport is more rapid
(d) passive transport is confined to anions while active transport is confined to cations
(b) passive transport is along the concentration gradient while active transport is due to metabolic energy
- A bottle filled with previously moistened mustard seeds and water was screw capped tightly and kept in a corner. It blew up suddenly after about half an hour. What is the phenomenon involved?
(a) diffusion
(b) imbibition
(c) osmosis
(d) d.P.D
(b) imbibition
- In a turgid cell, the turgor pressure is equal and opposite to the?
(a) Root pressure
(b) Wall pressure
(c) Diffusion pressure
(d) All of these
(b) Wall pressure
- Under what conditions is the DPD more than OP?
(a) When OP is equal to TP
(b) When OP is less than TP
(c) When OP is greater than TP
(d) When TP is negative
(d) When TP is negative
- What would the water potential be if the pressure potential was +0.16 megapascals (mPa) and the osmotic potential was –0.24 megapascals?
(a) + 0.4 mPa
(b) +0.08 mPa
(c) – 0.08 mPa
(d) + 0.16 mPa
(c) – 0.08 mPa
- What does imbibition cause?
(a) increase in the volume of imbibant but no pressure development.
(b) decrease in the volume of imbibant and pressure develops.
(c) no change in the volume of imbibant but pressure develops.
(d) the volume of imbibant increases and pressure develops.
(d) the volume of imbibant increases and pressure develops.
- Osmosis is the diffusion of?
(a) solute
(b) free energy
(c) water
(d) solute and solvent
(c) water
- When is root pressure maximum?
(a) Transpiration is high and absorption is very low
(b) Transpiration is very low and absorption is high
(c) Transpiration is very high and absorption is also high
(d) Transpiration and absorption both are show
(b) Transpiration is very low and absorption is high
- What is the primary function of the Casparian strip?
(a) force water and minerals through the membranes of endodermal cells.
(b) prevent entry into the stele solely through the apoplast.
(c) provide regulation for water and mineral movement in the plant.
(d) All of the above
(d) All of the above
- Why does the root cap have no role in water absorption?
(a) it has no direct connection with the vascular system.
(b) it has no cells containing chloroplasts.
(c) it has no root hairs.
(d) it has loosely arranged cells.
(c) it has no root hairs.
- Which of the following statement is false?
(a) Plants absorb an excess quantity of water
(b) Plants take small quantities of mineral salts through soil water
(c) Water and inorganic salts are taken simultaneously by root hairs
(d) Plants absorb only one thing at a time water or inorganic salts
(d) Plants absorb only one thing at a time water or inorganic salts
- What do guard cells help in?
(a) transpiration
(b) guttation
(c) fighting against infection
(d) protection against grazing
(a) transpiration
- In a solution, the osmotic pressure is?
(a) greater than the pure solvent.
(b) less than the pure solvent.
(c) equal to the pure solvent.
(d) less than or greater than the pure solvent.
(b) less than the pure solvent.
- Guttation is the result of what?
(a) diffusion
(b) transpiration
(c) osmosis
(d) root pressure
(d) root pressure
- What is the water potential of pure water and its solution?
(a) 0 and 1
(b) 0 and 0
(c) 0 and more than 1
(d) 0 and less than 1.
(d) 0 and less than 1.
- When will root hairs absorb water?
(a) Concentration of salts in the soil is high
(b) Concentration of solutes in the cell sap is high
(c) The plant is rapidly respiring
(d) They are separated from the soil by a semipermeable membrane
(b) Concentration of solutes in the cell sap is high
- What method of transport in the plasma membrane does not require a carrier molecule?
(a) Active transport
(b) Simple diffusion
(c) Facilitated diffusion
(d) Na+ – K+ pump
(b) Simple diffusion
- A boy is studying the transport of a certain type of molecule into a cell. When the cells are poisoned with a chemical that inhibits energy production, transport slows down. Normally, the molecules studied by the boy are transported by
(a) simple diffusion
(b) osmosis
(c) active transport
(d) facilitated diffusion
(c) active transport
- What is not true about the carrier molecules involved in facilitated diffusion?
(a) They increase the speed of transport across a membrane.
(b) They concentrate solute molecules on one side of the membrane.
(c) They have specific binding sites for the molecules they transport.
(d) They may undergo conformational change upon binding of solutes.
(b) They concentrate solute molecules on one side of the membrane.
- Water continues to enter a cell that is immersed in water until the?
(a) Concentration of the salts is the same inside the cell as outside
(b) Cell bursts
(c) Concentration of water is the same inside the cell as outside
(d) Diffusion pressure deficit is the same inside the cell as outside
(d) Diffusion pressure deficit is the same inside the cell as outside
- What does osmosis mean?
(a) Solute from low concentration to higher concentration
(b) Solute from higher concentration to low concentration
(c) Solvent from a low concentration of solution to a higher concentration of the solution
(d) Solvent from a higher concentration of solution to a low concentration of the solution
(c) Solvent from a low concentration of solution to a higher concentration of the solution
- What about water transport is true?
(a) Root pressure is sufficient to drive xylem sap movement.
(b) Bulk flow is not a mechanism by which water and minerals are transported.
(c) The cohesive nature of water is central to water movement in a plant.
(d) None of the above
(c) The cohesive nature of water is central to water movement in a plant.
- What is the movement of H2O through the cell wall called?
(a) Apoplast
(b) Symplast
(c) Tonoplast
(d) None of these
(a) Apoplast
- In soil, storage capacity refers to the amount of __ it can hold.
(a) Gravitational water
(b) Capillary water
(c) Hygroscopic water
(d) All of the above
(b) Capillary water
- What results in the passive absorption of water by the root system?
(a) Forces created in the cells of the root
(b) Increased respiratory activity in root cells
(c) Tension on the cell sap due to transpiration
(d) Osmotic force in the shoot system
(c) Tension on the cell sap due to transpiration
- A well-watered pot plant’s stump continuously excretes watery substance after cutting off the shoot slightly above the base. What causes this?
(a) Root pressure
(b) Guttation
(c) Transpiration
(d) Imbibition
(a) Root pressure
- A boy is studying the transport of a certain type of molecule into a cell. He finds that when cells are poisoned with a chemical that inhibits energy production, transport is slowed down. How are the molecules studied by the boy transported under normal circumstances?
(a) simple diffusion
(b) osmosis
(c) active transport
(d) facilitated diffusion
(c) active transport
- Which of the following statements is/are not true?
(i) Water and minerals, and food are generally moved by a mass or bulk flow system.
(ii) Bulk flow can be achieved either through a positive hydrostatic pressure gradient or a negative hydrostatic pressure gradient.
(iii) The bulk movement of substances through the conducting tissues of plants is called translocation.
(iv) Xylem translocates organic and inorganic solutes, mainly from roots to the aerial parts of the plants.
(v) Phloem translocates water, mineral salts, some organic nitrogen and hormones, from the leaves to other parts of the plants.
(a) (ii), (iii) and (v)
(b) (ii), (iii) and (iv)
(c) (iv) and (v)
(d) (ii) and (v)
(c) (iv) and (v)
- How does the xylem move its materials?
(a) from the leaves to the roots.
(b) from the roots to the leaves.
(c) when the plant is actively photosynthesizing.
(d) if the proper pressure is maintained.
(b) from the roots to the leaves.
- What is similar between primary and secondary active transport?
(a) Generate ATP
(b) Use ATP directly
(c) Can move solutes against their concentration gradient
(d) Include the passive movement of a glucose molecule
(c) Can move solutes against their concentration gradient
- What are aquaporins?
(a) cytoplasmic connections between cortex cells.
(b) openings in the lower epidermis of leaves through which water vapour escapes.
(c) openings into root hairs through which water enters.
(d) water-specific channels in membranes that may regulate the rate of osmosis.
(d) water-specific channels in membranes that may regulate the rate of osmosis.
- In a cell, Na+ / K+ pump is an example of?
(a) osmosis
(b) diffusion
(c) passive transport
(d) active transport
(d) active transport
- What happens to the pH of guard cells when the stomata opens?
(a) increases
(b) decreases
(c) remains same
(d) Both (a) and (b)
(a) increases
- Transpiration ratio is the ratio of moles of H2O transpired/ moles of CO2 fixed. This ratio is a measure of what?
(a) The efficiency of guard cells on stomatal movement
(b) Effectiveness of stomata is maximizing photosynthesis while minimizing water loss
(c) Distinguishing a xerophyte from a glycophyte
(d) Stomatal pore size of the leaves
(b) Effectiveness of stomata is maximizing photosynthesis while minimizing water loss
- Stomata opens when the guard cells are?
(a) Flaccid
(b) Functionless
(c) Dumb-bell shaped
(d) Turgid
(d) Turgid
- What is Ganong’s potometer used to measure?
(a) Photosynthesis
(b) Respiration
(c) Transpiration
(d) Guttation
(c) Transpiration
- What is the most common type of transpiration?
(a) Stomatal
(b) Lenticular
(c) Foliar
(d) Cuticular
(a) Stomatal
- A plant’s transpiration rate would gradually increase if?
(a) the relative humidity increases.
(b) the relative humidity decreases.
(c) the relative humidity remains unchanged.
(d) the water potential gradient remains unchanged.
(b) the relative humidity decreases.
- When dry seeds are placed in water, they swell up. This is because of?
(a) Imbibition
(b) Absorption
(c) Diffusion
(d) Adsorption
(a) Imbibition
- What is the most acceptable theory for how water moves through plants?
(a) Cohesion theory
(b) Passive transport
(c) Root pressure
(d) Capillarity
(a) Cohesion theory
- Ascent of sap in plants takes place through?
(a) Cambium
(b) Phloem
(c) Xylem
(d) Epidermis
(c) Xylem
- Which metal ion is involved in stomatal regulation?
(a) Iron
(b) Magnesium
(c) Zinc
(d) Potassium
(d) Potassium
- Which of the following are processes that occur in leaves which may lower their temperature?
(a) Respiration
(b) Photosynthesis
(c) Hydrolysis
(d) Transpiration
(d) Transpiration
- The stomata’s opening and closing are mainly dependent upon the change in the turgidity of?
(a) microfibrils
(b) guard cells
(c) epidermal cells
(d) xylem
(b) guard cells
- When will the speed of water absorption be greater?
(a) the difference between the osmotic pressure of soil water and that of xylem vessels is always less.
(b) the difference between the osmotic pressure of soil water and that of xylem vessels is always more.
(c) the osmotic pressure of soil water is always more than that of xylem vessels.
(d) the osmotic pressure of soil water is always less than that of xylem vessels.
(b) the difference between the osmotic pressure of soil water and that of xylem vessels is always more.
- Why do leaves that appear wilted during the day recover at night?
(a) Light is essential for photosynthesis
(b) The stomata close down, temperature decreases, transpiration is reduced and the plant can absorb more water from the soil
(c) Respiration and translocation of organic substances both increase
(d) The plant is sleeping because of dark conditions
(b) The stomata close down, temperature decreases, transpiration is reduced and the plant can absorb more water from the soil
- What does an increase in CO2 concentration around the leaf result in?
(a) Rapid opening of stomata
(b) Partial closure of stomata
(c) Complete closure of stomata
(d) No effect on stomatal opening
(b) Partial closure of stomata
- Which wall of guard cells is thick?
(a) Outer
(b) Inner
(c) Sidewall
(d) All the three
(b) Inner
- What does the spray of Phenyl Mercuric Acetate (PMA) cause?
(a) Decrease in transpiration
(b) Increase in transpiration
(c) Increase in absorption
(d) Increase in guttation
(a) Decrease in transpiration
- The pressure flow model predicts that during fruit development, photosynthesizing leaves are the ______ and the fruit is the _______.
(a) sink, sink
(b) sink, source
(c) source, sink
(d) source, source
(c) source, sink
- The rate of respiration of plants is measured in still air as well as with a fan blowing air over them. The rate of transpiration will be
(a) greater first time
(b) greater second time
(c) equal both the times
(d) None of these
(b) greater second time
- The structure of stomata is not related to which of the following cells?
(a) Epidermal cells
(b) Guard cells
(c) Sclerenchymatous cells
(d) Accessory cells.
(c) Sclerenchymatous cells
- What is the Ringing experiment related to?
(a) Ascent of sap
(b) Translocation of food
(c) Both (a) and (b)
(d) Mineral nutrition
(c) Both (a) and (b)
- In guttation, water lost is?
(a) pure water
(b) impure water
(c) in vapour form
(d) Either (a) or (b)
(b) impure water
- What are sinks related to?
(a) Transport of minerals
(b) Stomata
(c) Enzymes
(d) Phytochrome
(a) Transport of minerals
- Minerals are translocated bidirectionally in?
(a) Xylem
(b) Phloem
(c) Parenchyma
(d) Cambium
(b) Phloem
- What is the movement of materials through the vascular tissue of plants?
(a) Transpiration
(b) Translocation
(c) Transcription
(d) Transduction
(b) Translocation
- What does addition of a solute to pure water cause?
(a) negative water potential.
(b) more negative water potential.
(c) positive water potential.
(d) more positive water potential.
(a) negative water potential.
- What is the cause of the flow of soluble substances according to Munch’s theory?
(a) Protoplasmic flow
(b) Mass flow due to reduction in turgor pressure
(c) Diffusion
(d) None of these
(b) Mass flow due to reduction in turgor pressure
- The movement of sucrose from source to sink can be explained by what mechanism?
(a) Evaporation of water and active transport of sucrose from the sink.
(b) Osmotic movement of water into the sucrose-loaded sieve-tube cells creates a higher hydrostatic pressure in the source than in the sink.
(c) Tension created by the differences in hydrostatic pressure in the source and sink.
(d) Active transport of sucrose through the sieve-tube members driven by proton pumps.
(b) Osmotic movement of water into the sucrose-loaded sieve-tube cells creates a higher hydrostatic pressure in the source than in the sink.
- Na+ / K+ pump in a cell is an example of what?
(a) osmosis
(b) diffusion
(c) passive transport
(d) active transport
(d) active transport
- What is the reason for the Venus fly trap’s ability to capture insects?
(a) specialised “muscle-like” cells
(b) chemical stimulation by the prey
(c) a passive process requiring no special ability on the part of the plant
(d) rapid turgor pressure changes
(d) rapid turgor pressure changes
- What supports the translocation of organic solutes in sieve tube members?
(a) P-proteins
(b) mass flow involving a carrier and ATP
(c) cytoplasmic streaming
(d) root pressure and transpiration pull
(a) P-proteins
- What is the result of phenyl mercuric acetate (PMA)?
(a) reduced photosynthesis
(b) reduced transpiration
(c) reduced respiration
(d) killing of plants
(b) reduced transpiration
- There will be no transpiration in which of the following plants?
(a) Aquatic submerged plants
(b) Plants living in deserts
(c) Aquatic plants with floating leaves
(d) Plants growing in hilly regions
(a) Aquatic submerged plants
- When will transpiration in plants be the lowest?
(a) When there is high humidity in the atmosphere
(b) High wind velocity
(c) There is an excess of water in the cell
(d) Environmental conditions are very dry
(a) When there is high humidity in the atmosphere
- Na+, K+ dependent ATPase activity contributes to the transport of?
(a) K+ inward, Na+ outward
(b) K+ inward only
(c) Na+ inward only
(d) K+ outward, Na+ inward
(a) K+ inward, Na+ outward
- What is the force developed in the cortex of the root which pushes water into the xylem of root soil?
(a) diffusion
(b) osmotic pressure
(c) turgor pressure
(d) root pressure
(b) osmotic pressure
- Active transport of solutes in plants refers to the flow of solutes against a concentration gradient and therefore requires an input of energy. From where is this energy derived?
(a) Always from hydrolysis of ATP
(b) Not only from ATP hydrolysis but also from the collapse of a proton motive force
(c) Partly from the input from ATP hydrolysis and partly from the collapse of a proton motive force
(d) From the different sources depending on the solutes
(a) Always from hydrolysis of ATP
- The water available for root absorption in the soil is?
(a) gravitational water
(b) capillary water
(c) hygroscopic water
(d) combined water
(b) capillary water
- Xylem and phloem transport differ in which of the following ways?
(a) Active transport moves the xylem but not the phloem sap.
(b) Transpiration moves phloem sap but not xylem sap.
(c) Xylem sap moves up; phloem sap moves up and down.
(d) Xylem moves from sugar source to sink but phloem does not.
(c) Xylem sap moves up; phloem sap moves up and down.
- Facilitated transport does not meet which of the following criteria?
(a) High selectivity
(b) Transport saturation
(c) Uphill transport
(d) Requirement of special membrane proteins
(c) Uphill transport
- What is the force that is developed in the cortex of the root which pushes water into the xylem of the root from the soil?
(a) Diffusion
(b) Osmotic pressure
(c) Turgor pressure
(d) Root pressure
(b) Osmotic pressure
- When the stomata closes, which of the following does not occur?
(a) Guard cells become flaccid
(b) Sugar is converted to starch
(c) O.P. of the guard cell decreases
(d) Accumulation of O2 takes place
(d) Accumulation of O2 takes place
- When does wilting occur?
(a) Rate of transpiration is higher than the absorption
(b) Rate of absorption is higher than transpiration
(c) Excess root pressure
(d) High relative humidity in the air
(a) Rate of transpiration is higher than the absorption
- What is the Casparian strip made up of?
(a) lignin
(b) pectin
(c) suberin
(d) cellulose
(c) suberin
- The accumulation of K+ ions in guard cells will have what effect?
(a) Water potential increases
(b) Water potential decreases
(c) Loss of turgidity
(d) Exosmosis
(b) Water potential decreases
- A stomatal closure occurs when which of the following is produced during water stress?
(a) Cytokinin
(b) Auxin
(c) GA3
(d) ABA
(d) ABA