AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

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Students get through AP Inter 2nd Year Botany Important Questions 1st Lesson Transport in Plants which are most likely to be asked in the exam.

AP Inter 2nd Year Botany Important Questions 1st Lesson Transport in Plants

Very Short Answer Questions

Question 1.
Whatareporins? What role do they play in diffusion?
Answer:

  1. Porins are a kind of protein channel.
  2. They form huge pores on the outer membranes of plastids, mitochondria and some bacteria.
  3. They allow small-sized protein molecules to diffuse through them.
  4. Thus, porins cause facilitated diffusion.

Question 2.
Define water potential. What is the value of the water potential of pure water? [TS 20]
Answer:

  1. Water potential(ψw): The measure of the relative tendency of water to move from one part to another part is called water potential.
  2. The value of the water potential of pure water is taken as zero.

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants
Question 3.
Differentiate osmosis from diffusion. [AP MAR, MAY-17]
Answer:

Osmosis Diffusion
1) Osmosis is the movement of solvent (water) molecules from a lower concentrate solution to a higher concentrated solution. 1) Diffusion is the movement of solute molecules from a higher concentrated solution to a lower concentrated solution.
2) It requires a semipermeable membrane. 2) It need not require a membrane.
3) It occurs in a liquid medium only. 3) It occurs mostly in gases and liquids.
4) Ex: Osmosis of water across Plant cells. 4) Ex: Diffusion of gases (CO2 and O2) during photosynthesis.

Question 4.
Compare transpiration and evaporation.
Answer:

 

Transpiration Evaporation
1) Transpiration is the loss of water from the living tissues of aerial parts of plants in the form of vapour. 1) Evaporation is the loss of water from any free surface i.e., either living or non-living
2) It happens within the plant. 2) It is a surface-level process.
3) It is a physiological process. 3) is a physical process.
4) It is a slow process. 4) It is comparatively a fast process.

Question 5.
What are apoplast and symplast? [AP MAY-22] [AP MAR-19] [TS MAR-17,15]
Answer:

Apoplast Symplast
1) Apoplast is the path of transport of water in a plant without crossing any membrane. 2) It is a fast process.
1) Symplast is the path of transport of water in a plant by crossing some membranes. 2) It is a slow process

Question 6.
How does guttation differ from transpiration? [TS MAR-15]
Answer:

 

Guttation Transpiration
1) During guttation, water is lost from the leaves of plants in the form of water droplets. 1) During transpiration, water is lost from the leaves of plants in the form of wafer vapour.
2) It occurs usually at night. 2) It occurs usually at day time.
3) It is an uncontrolled process. 3) It is a controlled process.

Question 7.
What happens when a pressure greater than the atmospheric pressure is applied to pure water or a solution?
Answer:

  1. For pure water, water potential is zero, at normal atmospheric pressure.
  2. So when pressure greater than atmospheric pressure is applied to pure water its water potential increases i.e., becomes more than zero.

Question 8.
Explain what will happen to a plant cell if it is kept in a solution having higher water potential.
Answer:

  1. If a plant cell is kept in a solution having higher water potential, the cell absorbs water and becomes turgid.
  2. Then its water potential increases.

Question 9.
What are the physical factors responsible for the ascent of sap through the xylem in plants? [TS MAR-17|
Answer:
Physical factors responsible for the ascent of sap:

  1. Cohesion: Mutual attraction between water molecules.
  2. Adhesion: Attraction of water molecules to the surface of tracheal elements.
  3. Transpiration pull: Driving force for upward movement of water.

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

Question 10.
Explain why xylem transport is unidirectional while that in phloem is bidirectional.
Answer:

  1. The xylem transports water and minerals from the roots to the leaves in an upward direction due to transpiration pull. Hence it is unidirectional.
  2. Generally, the phloem transfers the ‘synthesized food’ in the leaves (source) of the plant to the required parts(sink).
  3. But during the spring season, the process is reversed, as the food stored in the sink moves towards the growing buds of the plant. So transport in phloem is bidirectional (Upward and downward) due to Translocation.

Question 11.
With reference to the transportation of food within a plant, what are source and sink? [TS MAR-19]
Answer:

  1. Source: It is a place in the plant body where food material is prepared Ex: leaf.
  2. Sink: It is a place in the plant body where food material is stored. Ex: fruits, buds.

Question 12.
Does transpiration occur at night? Give an example.
Answer:

  1. Yes, transpiration occurs at night.
  2. Ex: BryophyHum, Cacti.

Question 13.
Compare the pH of guard cells during the opening and closing of stomata.
Answer:

  1. The pH of guard cells increases during the opening of stomata.
  2. The pH of guard cells decreases during the closing of stomata.

Question 14.
In the wake of transpirational loss, why do the C4 plants are more efficient than C3 plants?
Answer:

  1. C4 plants minimise water loss and hence they fix more CO2 than C3 plants.
  2. C4 plants loss only half as much water as a C3 plant for the same amount of C02 fixed.

Question 15.
What is meant by transport saturation? How does it influence facilitated diffusion?
Answer:

  1. When all the protein transporters are used, the process of transport reaches to a saturation point. It is called transport saturation. At this stage, transport will be maximum.
  2. Transport saturation increases facilitated diffusion.

Question 16.
Pressure potential in plant systems can be negative. Elaborate.
Answer:

  1. Pressure potential in turgid plant cells is usually positive.
  2. But in Xylem cells there is negative pressure potential due to transpiration.
  3. In Flaccid cells, the plasma membrane will be pulled away from the cell wall. Hence pressure potential becomes negative.

Question 17.
How does ABA bring about the closure of stomata under water stress conditions? [AP – 20]
Answer:
Under water stress conditions, ABA( Abscisic acid) drives the K+ ions out of guard cells and makes them close.

Question 18.
Compare imbibing capacities of pea and wheat seeds. [TS -16]
Answer:

  1. Proteinaceous pea seeds imbibe more water and swell more than starchy wheat seeds.
  2. Because when compared to carbohydrates, the imbibing capacity of proteins is more.

Short Answer Questions

Question 1.
Define and explain water potential.
Answer:
Water potential(ψw): Water potential is the measure of the relative tendency of water to move from one part to another part through diffusion, and osmosis.
It is expressed in Pascals (Pa).
The water potential of Pure water is taken as zero at standard temperature and pressure.
Water potential has two main components (i) Solute potential and (ii) Pressure potential.

i) Solute potential (ψs): When a solute is dissolved in pure water, the concentration of pure water decreases. Hence its water potential also decreases. This decrease in water potential is called solute potential. It is always negative.

ii) Pressure potential (ψp): When some water enters into a plant cell, due to diffusion the pressure against cell wall increases. This makes the cell turgid(swollen). This increase in water potential is called pressure potential. It is always positive. It is observed in the ascent of water through the stem.
We have, Water potential ψw = ψs + ψp.
Thus, the water potential of a cell is always affected by both solute potential and pressure potential.

Question 2.
Write short notes on facilitated diffusion.
Answer:

  1. Facilitated diffusion: It is the diffusion of small protein molecules through porins.
  2. The diffusion of any substance across a membrane also depends on its solubility in lipids.
  3. Generally, substances soluble in lipids diffuse faster through the cell membrane.
  4. But substances that have a hydrophilic moiety find it difficult to pass through the membrane.
  5. Then their movement has to be facilitated.
  6. Some special proteins help to move substances across the membrane without utilising ATP energy.
  7. Some membrane proteins provide sites, at which such molecules cross the membrane.
  8. Such a kind of diffusion which facilitates the diffusion process is called Facilitated diffusion.
  9. Facilitated diffusion is sensitive to inhibitors because they react with protein side chains.

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

Question 3.
What is meant by plasmolysis? How is it practically useful to us? [AP MAR-16]
Answer:

  1. Plasmolysis: It is the shrinkage of the protoplast of cell due to loss of water and turgor.
  2. This happens when a plant cell is placed in a hypertonic solution.
  3. Water molecules inside the clove out into the solution.
  4. Then the cell membrane shrinks away from its cell wall.
  5. This causes the protoplast to shrink away from the wall.
  6. This leads to the separation of the plasma membrane from the cell wall.
  7. Then the cell is said to be plasmolysed.
  8. If the plasmolysed cell is again placed immediately in a hypotonic solution, it will quickly regain its water loss by osmosis.
  9. This process is called deplasmolysis.
  10. Practical applications: Salting of pickles, preservation of fish, meat and prawns.

Question 4.
How does the ascent of sap occur in tall trees? [AP, TS MAR-15]
Answer:

  1. Ascent of sap: It is the upward movement of water through the xylem against gravitational force.
  2. Transpiration plays a significant role in the ascent of sap.
  3. The transpiration-driven ascent of xylem sap depends on the following 3 physical properties.
    (a) Cohesion – the mutual attraction between water molecules.
    (b) Adhesion – attraction of water molecules to polar surfaces.
    (c)Transpiration pull – driving force for upward movement of water.
  4. These properties give water a high tensile strength, i.e., an ability to resist a pulling force, and
    high capillarity, i.e., the ability to rise in thin tubes.
  5. The process of photosynthesis requires water.
  6. The system of xylem vessels from the root to the leaf supplies the needed water.
  7. The evaporation of water through the stomata of leaves creates the ‘transpiration puli’.

Question 5.
Stomata are Turgor-operated valves. Explain
Answer:

  1. Opening and closing of stomata is due to changes in the turgidity of guard cells.
  2. Inner wall of the guard cell towards the pore is thick and elastic.
  3. When turgidity increases, the thin outer wall forces the inner wall into a crescent shape.
  4. When guard cells lose water, inner walls regain their original shape, guard cells become flaccid and stomata close.
  5. Hence, stomata are turgor-operated valves.

Question 6.
Explain the Pressure flow hypothesis of the translocation of sugars in plants.
Answer:

  1. Pressure flow (Mass flow hypothesis): Food is prepared in the plant leaves in the form of glucose.
  2. Glucose is converted into sucrose.
  3. It is moved into companion cells.
    AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants 1
  4. Thereby, they enter into sieve tubes of phloem by active transport. .
  5. Thus hypertonic condition in the phloem is established.
  6. Water from the adjacent xylem moves into the phloem by osmosis.
  7. Osmotic pressure builds up in phloem sap.
  8. It moves to areas of lower pressure and finally sinks.
  9. At the sink, sugar is converted into starch and stored.
  10. The starch is finally removed from the sink cells through active transport. ,

Question 7.
“Transpiration is a necessary evil”. Explain. [AP MAR-17, 20)(AP, MAY-17, 22) [TS 16, 17, 20]
Answer:
Transpiration has both advantages and disadvantages as well, to plants. So it is a ’necessary evil’.
A) Advantages of Transpiration:

  1. It creates ‘transpiration puli’ for the absorption and transportation of water in plants.
  2. It supplies water for photosynthesis.
  3. It transports minerals from the soil to all parts of the plant.
  4. It cools leaf surfaces by evaporative cooling.
  5. It maintains the shape and structure of plants by keeping cells turgid.

B) Disadvantages of Transpiration:

  1. Excessive transpiration makes the cells flaccid.’
  2. This retards the growth of plants.
  3. More amount of water is evaporated by transpiration.
  4. Thus photosynthesis is limited by the available water.

Question 8.
A gardener forgot to water a potted plant for a day in summer. What will happen to the plant? Do you think it is reversible? Explain.
Answer:

  1. In hot summer, the leaves of plants lose water due to transpiration.
  2. So plants suffer from temporary wilting
  3. Afterwards, when the plant is watered, it absorbs water. The cells of leaf become turgid and regain normalcy.
  4. Suppose if we do not water for one more day, it suffers from permanent wilting.
  5. It cannot regain its original shape and structure.
  6. Finally, plants suffer from death.

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

Question 9.
Explain the type of molecular movement which is highly selective and requires special membrane proteins, but doesn’t require any energy.
Answer:
In facilitated diffusion, the molecular movements are

  1. Highly selective
  2. require special membrane proteins
  3. but do not require any energy.

(i) Highly Selective: During facilitated diffusion, the membrane proteins regulate the passage of material which cannot freely cross. So the molecular movements are highly selective during facilitated diffusion.

(ii) Special Proteins: In simple diffusion, the random movement of molecules takes place from higher concentration to lower concentration till equilibrium is reached. But in facilitated diffusion, the membrane provides some ‘special proteins called porins’ to move molecular sub¬stances across the membrane.

(iii) No energy: Facilitated diffusion is a passive transport because the movement of material is along a concentration gradient. So it does not require the expenditure of energy ( ATP hydrolysis).

Question 10.
How does most of the water move within a healthy plant body and by which path?
Answer:
In plants, initially, water is absorbed from the root hairs by diffusion. Then water moves by two distinct pathways.

  1. Apoplast
  2. Symplast

1) Apoplast: It is the path of transport of water in a plant without crossing any membrane.
The cortical cells in the cortex are loosely arranged. So there is low resistance to the water flow. So most of the water flows through those intercellular spaces of plant tissues. Hence apoplast is a fast process.

2) Symplast: It is the path of transport of water in a plant by crossing some membranes. Endodermis walls are thick and thick with Casparian strip. So there is high resistance to water flow. In symplast, water reaches the xylem through vascular bundles this symplast is a slow process.

Question 11.
Transpiration and Photosynthesis-a compromise. Explain. [TS MAR-19]
Answer:

  1. Photosynthesis requires continuous water supply because plants are insatiable need of water.
  2. So, plants open their stomata to exchange gases.
  3. But the opening of stomata causes ‘loss of water by evaporation.
  4. This causes water to be ‘pulled up’ from the soil, leading to transpiration.
  5. Thus transpiration supplies the water required for photosynthesis.
  6. Hence, transpiration and photosynthesis become compromising processes to each other.

Question 12.
Do different species of plants growing in the same area show the same rate of transpira¬tion at a particular time? Justify your answer.
Answer:
No.
Transpiration is the loss of water in the form of vapour, from the living tissues of aerial parts of the plants.
Different species of plants, growing in same area, do not show the same rate of transpiration at a particular time.
Because the rate of transpiration depends on several factors like

  1. Leaf size
  2. Leaf structure
  3. Leaf surface area
  4. Water absorption
  5. Number distribution of stomata
  6. pH of guard cells,
  7. Plant origin etc.

Ex: A mature com plant absorbs almost three litres of water in a day, while a mustard plant absorbs water equal to its own weight in about 5 hours.

Question 13.
Explain the structure and mechanism of opening and closing of stomata.[TS MAR-15]
Answer:
Levitt’s K+ ion pump theory:

  1. According to this theory, K+ ions accumulate in the guard cells from the subsidiary cells in the presence of light.
  2. This is coupled with an efflux of protons which leads to an increase in the pH of guard cells.
  3. This is also associated with the passive in flux of Cl– ions, thereby decreasing the water potential of guard cells.
    AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants 2
  4. Water thereby enters into guard cells, making them turgid.
  5. The outer walls of guard cells are thin and expand outwardly, leaving a minute pore in the centre to open.
  6. At night, in the absence of light, K+ and Cl– ions move out of guard cells, due to which the water potential of guard cells increases. Hence, water moves out and the stomata closes.
  7. Under water stress conditions Abscisic acid (ABA), a natural antitranspirant drives the K+ions out of guard cells making them close.
  8.  In succulent plants, the water potential gradient is established. Accumulation of organic acids at night makes the guard cells turgid, hence stomata open at night.

Long Answer Questions

Question 1.
Explain how plants absorb water.
Answer:
Plants absorb water in two ways. I) Apoplastic pathway II) symplastic pathway.
I. Apoplastic Pathway:

  1. It is the path of transport of water in a plant without crossing any membrane.
  2. The majority of water is transported in this way.
  3. It flows through intercellular spaces from root to xylem except at Casparian strips of endodermis.
    AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants 3
  4. This pathway doesn’t involve the crossing of membranes.
  5. It is dependent on the gradient and mass flow.
  6. As water evaporates, tension develops in the apoplast and mass flow occurs due to the adhesive & cohesive forces of water.

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

II. Symplastic Pathway:

  1. It is the path of transport of water in a plant by crossing some membranes through cytoplasm of cells.
  2. Intercellular movement is through plasmo desmeta (cytoplasmic strands connecting neighbouring cells.)
  3. The movement is relatively slower. It may be aided by cytoplasmic streaming.
  4. Once inside the xylem, water becomes free to move between cells. Various ions are transported to the roots and water follows the potential gradient.
  5. It increases pressure inside xylem which is called root pressure.
  6. It is responsible for pushing up water to small heights in the plants.
  7. Here the plants absorb water by osmosis.

Question 2.
Define transpiration. Explain the structure and the mechanism of opening and closing of stomata.
Answer:
Transpiration: It is the loss of water in the form of vapour, from the living tissues of aerial parts of the plants.
Structure of Stomata:

  1. Stomata are small pores in the epidermis of leaf through which transpiration occurs.
  2. In dicots, each stoma is composed of two bean (kidney) shaped cells known as guard cells.
  3. In grasses, the guard cells are in a dumbbell shape.
    AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants 4
  4. The guard cells possess chloroplasts.
  5. The outer walls of guard cells are thin and inner walls are thick.
  6. The neighbouring cells are called subsidiary cells.
  7. Stomatal apparatus consists of (i) stomatal aperture (ii)guard cells (iii) subsidiary cells

Opening and closing of stomata:

  1. The opening or closing of stomata is due to changes in the turgidity of guard cells.
  2. When turgidity increases within the two guard cells, the thin outer walls bulge out and the stomata opens.
  3. When the guard cells lose turgor due to water loss, the elastic inner walls regain their original shape, the guard cells become flaccid and the stomata closes.

Mechanism – Levitt’s K+ ion pump theory:

  1. According to Levitt’s theory, K+ ons accumulate iij {he guard cells which come from the subsidiary cells in the presence of light.
  2. This is coupled with efflux of protons which leads to an increase in the pH of guard cells.
  3. This is also associated with the passive in flux of Cl– ions, thereby decreasing the water potential of guard cells.
    AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants 5
  4. Water thereby enters into guard cells, making them turgid.
  5. The outer walls of guard cells are thin and expand outwardly, leaving a minute pore in the centre to open.
  6. At night, in the absence of light, K+ and Cl– ions move out of guard cells, due to which the water potential of guard cells increases. Hence, water moves out and the stomata closes.
  7. Under water stress conditions Abscisic acid (ABA), a natural antitranspirant drives the K+ions out of guard cells which makes them close.
  8. In succulent plants, the water potential gradient is established. Accumulation of organic acids at night makes the guard cells turgid, hence stomata opens at night.

Exercise

Question 1.
Differentiate uphill and downhill transport.
Answer:
Uphill transport Downhill transport

Uphill transport Downhill transport
1) During this process the molecules move from a lower concentration to a higher concentration. 1) During this process the molecules move from a higher concentration to lower concentration.
2) Utilisation of energy to pump molecules against concentration gradient is called active transport. 2) Transport of molecules without utilising energy (ATP) is called passive transport.

Question 2.
Compare facilitated diffusion and simple diffusion.
Answer:
Simple Diffusion: It is the random movement of molecules from a region of higher concentration into a region of lower concentration.
Facilitated Diffusion: In this type, molecular movement is highly selective and requires special membrane proteins. These proteins form channels in the membrane. Through these channels, the molecules pass through.

Question 3.
What happens when two solutions of different concentrations are separated by egg membrane? State the reason.
Answer:
“Osmosis” takes place when two solutions of different concentrations are separated by egg membrane. The direction and rate of osmosis depend on both the pressure gradient and concentration gradient. ‘

Question 4.
In general in a plant which path of water movement is more and why?
Answer:

  1. The apoplastic path of water movement is more.
  2. The cortical cells are loosely packed and they offer no resistance up to endodermis.
  3. The radial walls of endodermis contain suberised casparian thickenings.
  4. There the water flow is by symplast and through pericycle, water ultimately reaches xylem vessels.

Question 5.
Why do pinus seeds fail to germinate in the absence of mycorrhizae?
Answer:
Mycorrhizae is the symbiotic association between fungi and the root system of higher plants. During this process the fungus provides water and minerals to the root, in turn, the root provides sugars and nitrates to the mycorrhizae. The Pinus plant has an obligate association with the mycorrhizae. So pinus seeds fail to germinate in the absence of mycorrhizae.

Question 6.
Why do stomata close under water stress conditions?
Answer:
Under water stress conditions, Abscisic acid (ABA) a natural anti transpirant drives the K+ ions out of guard cells making them close.

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

Question 7.
How are stomata distributed in a typical monocot plant?
Answer:
In a typical monocot plant, the stomata are distributed equally on both the upper and lower surfaces of the leaf.

Question 8.
In what form sugars are transported through phloem?
Answer:
Sucrose.

Question 9.
Why does the root endodermis transport ions in one direction only?
Answer:
Casparian strips are present on the radial walls of the endodermis. Here, symplastic movement of water and solutes occurs and reaches the xylem vessels. Thus in the endodermis, the transportation of ion occur only in one direction.

Question 10.
If a ring of bark is removed from an actively growing plant, what will happen and why?
Answer:
If the ring bark is removed, the portion of the plant above the ring swells after a few weeks. It is due to the accumulation of food. Phloem is responsible for the translocation of food from aerial parts of the plant to the roots in one direction only.

Multiple Choice Questions

Question 1.
A cell increases in size when placed in an external solution, which is
1. Hypotonic
2. Hypertonic
3. Isotonic
4. higher solution concentrated solution
Answer:
1. Hypotonic

Question 2.
Bacteria cannot survive in a highly salted pickle because
1. they get de-plasmolyse
2. they get plasmolysed and died
3. nutrients in pickles cannot support life
4. no photosynthesis occurs in a pickle
Answer:
2. they get plasmolysed and died

Question 3.
Cell walls and intercellular spaces of tissues are together called
1. Protoplast
2. Symplast
3. Apoplast
4. Leucoplast
Answer:
3. Apoplast

Question 4.
Diffusion in plants is also an important factor for
1. Keeping plant cells turgor
2. Supply of CO2 for photosynthesis
3. Opening and closing of flowers
4. building resistance to drought and frost
Answer:
2. Supply of CO2 for photosynthesis

Question 5.
Excess water is removed through the tips of the leaves of plants. This is called
1. Transpiration
2. Translocation
3. Guttation
4. Diffusion
Answer:
3. Guttation

Question 6.
Food synthesized in leaves is transported to other parts by
1. Translocation
2. Nastic movement
3. Chemotaxis
4. Phototaxis
Answer:
1. Translocation

Question 7.
Guttation is mainly due to
1. Root pressure
2. Osmosis
3. Transpiration
4. Imbibition
Answer:
1. Root pressure

Question 8.
Imbibition is involved in
1. Supply of CO2 during photosynthesis
2. Opening and closing movement of stomata
3. For the germination of seeds
4. Movement of water from one cell to another cell
Answer:
3. For the germination of seeds

Question 9.
K+ pump theory was proposed by
1. Joseph’s priestly
2. eurtis
3. Black slee
4. Levitt
Answer:
4. Levitt

Question 10.
Pumps are helpful in
1. Facilitated diffusion
2. Active transport
3. Diffusion
4. Passive transport
Answer:
2. Active transport

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

Question 11.
Root pressure is maximum when transpiration is
1. high & absorption is low
2. very low & absorption is high
3. very high & absorption is high
4. low and absorption is slow
Answer:
2. very low & absorption is high

Question 12.
Stomata open when
1. Guard cells loose K+ ions
2. pH of guard cells is high
3. CO2 cone, in guard cells is high
4. Accumulated malate is consumed in guard cells
Answer:
2. pH of guard cells is high

Question 13.
Transpiration and root pressure cause water to rise in plants by
1. Pushing it upward
2. pushing and pulling it, respectively
3. pulling it upward
4. pulling and pushing it, respectively
Answer:
4. pulling and pushing it, respectively

Question 14.
In Facilitated diffusion, the rate of transport of molecules depends on
1. Against concentration gradient
2. Utilisation of ATP
3. Saturation of transporters
4. Transpiration puli
Answer:
3. Saturation of transporters

Question 15.
Porins are made up of
1. Lipids & Proteins
2. Proteins only
3. Glucose
4. Glycoproteins
Answer:
2. Proteins only

Question 16.
Select the false statement regarding diffusion
1. It takes place through membrane only
2. It is a physical process
3. It is a passive process
4. It is driven by concentration differences
Answer:
1. It takes place through membrane only

Question 17.
Water potential value is the highest for
1. Hypertonic solution
2. Hypotonic solution
3. Isotonic solution
4. Pure water
Answer:
4. Pure water

Question 18.
In the apoplast pathway, water moves exclusively through the
1. Plasmodesmata
2. Cell walls
3. Intercellular spaces
4. 2&3
Answer:
4. 2&3

Question 19.
………….. cells show higher water potential
1. Endodermis
2. Epidermis
3. Xylem
4. Pericycle
Answer:
2. Epidermis

Question 20.
Water will be absorbed by root hairs when the external medium is
1. Hypotonic
2. Hypertonic
3. Isotonic
4. Viscous
Answer:
1. Hypotonic

Question 21.
Seeds and dry wood absorb water by
1. Imbibition
2. Osmosis
3. Diffusion
4. Plasmolysis
Answer:
1. Imbibition

Question 22.
Short-distance transport of substances within a plant takes place by
1. Osmosis
2. Bulk flow
3. Diffusion
4. Imbibition
Answer:
3. Diffusion

Question 23.
The process of plasmolysis is usually
1. Reversible
2. Irreversible
3. Multidirectional
4. Bidirectional
Answer:
1. Reversible

Question 24.
The process of water absorbed by solids/colloids is called
1. Osmosis
2. Imbibition
3. Plasmolysis
4. Diffusion
Answer:
2. Imbibition

Question 25.
Osmosis is a type of
1. Imbibition of solution
2. Diffusion of solvent
3. Evaporation of water
4. Diffusion of solute
Answer:
2. Diffusion of solvent

Question 26.
If the cell membrane of a plant cell shrinks away from its cell wall, it is due to
1. Osmosis
2. Plasmolysis
3. Diffusion
4. Imbibition
Answer:
2. Plasmolysis

AP Inter 2nd Year Botany Important Questions Chapter 1 Transport in Plants

Question 27.
Xylem is not associated with the translocation of
1. Mainly water
2. Mineral salts
3. Some organic nitrogen & hormones
4. Organic solutes
Answer:
4. Organic solutes

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