வேதநதி

TRANSPORT IN HIGHER PLANTS

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Section-A

1.Transpiration is manifestation of

Turgor pressure
Wall pressure
Root pressure
None of these
The loss of water from the living tissue of aerial parts of plant in the form of water vapour is called transpiration. More than 95% of total loss of water takes place through stomata. Opening and closing of stomata occurs due to turgor change in guard cells.

2.Select the correct events leading to the opening of the stomata.
I.Decline in guard cell solutes.
II.Lowering of osmotic potential of guard cells.
III.Rise in potassium levels in guard cells.
IV.Movement of water from neighbouring cells into guard cells.
V.Guard cells becoming flaccid.

I and V
II, III and IV
I, III and IV
II, IV and V
Levitt (1974) proposed ATP-driven $H^+-K^+$ exchange pump mechanism in guard cells for the stomatal opening and closing. According to it, there is accumulation of $K^+$ ions in the guard cells during day time. When guard cells possess more $K^+$, endosmosis takes place lowering the osmotic potential of guard cells, they become turgid and stomatal opening takes place.

3.Direction of translocation of organic food or solutes, is

Upward
Downward
Radial
All of these
The food material synthesizes in leaves of green plants and from seed during germination is translocated to growing regions and storage organs of plant

4.Which of the following is not correct regarding carrier molecules, involved in facilitated diffusion?

They are responsible to concentrate solute molecules on the side of membrane
They are responsible to increase the speed of transport across a membrane
They may be under conformational change upon binding of solutes
They possess specific binding sites for molecules to be transported
Carrier molecules or carrier proteins involved in facilitated diffusion, facilitate the diffusion of hydrophilic substances through biological membrane. They are specific and allow the cells to select solute of an appropriate size to be transported. Carrier proteins can increase the rate of diffusion and may undergo change upon binding to solutes

5.Loss of water in liquid phase (in form of droplets) from the margin of leaves in many herbaceous plants is

Guttation
Root pressure
Transpiration
Transpiration pull
Loss of water in liquid phase from the margin and tips of leaves in many herbaceous plant is referred to as guttation. Bergerstein first studied the phenomenon of guttation in 1887. Guttation is not observed in all plants, it is observed in cereals like wheat, maize, oat, etc.

6.Cell-A has osmotic potential of -18 bars and pressure potential of 8 bars, whereas, cell-B has osmotic potential of -14 bars and pressure potential 2 bars. The direction of flow of water will be

From cell-B to cell-A
From cell-A to cell-B
No flow of water
In both the directions
The water potential (Ψ) is equal to osmotic potential ($Ψ_s$) + pressure potential ($Ψ_p$). Osmotic potential is always in negative value. The water potential is the chemical potential of water, which is equivalent to DPD with negative sign.
Therefore, water potential ($Ψ_A$) of cell-A is
$Ψ_A=Ψ_s+Ψ_p=-18+8=-10$
Water potential of cell-B($ψ_B$) is
$Ψ_B=Ψ_s+Ψ_p=-14+2=-12$
Since, water moves from higher water potential, the flow of water will be from cell-A (-10 bars) to cell-B (-12 bars).

7.Passive absorption of mineral salts is not dependent on

Diffusion
Osmosis
Donnan equilibrium
Ionic exchange
Passive absorption of minerals takes place as mass flow, simple diffusion, facilitated diffusion, ion exchange, Donnan equilibrium.

8.A thin film of water is held by the soil particles under the influence of internal attractive force. It is called

Hygroscopic water
Gravitational water
Combined water
Capillary water
The water remaining in dry soil and held as very thin films around the soil particles is called hygroscopic water.

9.Guard cells control

Intensity of light entering
Photosynthesis
Closing and opening of stomata
Change in green color
Stomata are minute pore complexes found mainly in the epidermis of leaves. Each stoma is surrounded by two small but specialized green epidermal cells called guard cells. Their walls are differentially thickend and elastic. They control opening and closing of stomata.

10.Why is active transport considered important?

Because material is transported from higher concentration to lower concentration
Because material is transported from lower concentration to higher concentration
Because it increases diffusion coefficient
Because it does not use ATP
Active transport is a fast process comparative to passive transport and it occurs against the concentration gradient, i.e., material substances are transported from a region of lower concentration to higher concentration. While in diffusion, transport of substances occur along the concentration gradient

11.If flowers are cut and dipped in dilute NaCl solution, then

Transpiration is low
Endosmosis occurs
No bacterial growth takes place
Absorption of solute inside flower cell takes place
Dilute NaCl solution acts as hypotonic solution. So, when flowers are cut dipped in dilute NaCl solution, endosmosis occurs and the cells of flowers swell.

12.Which one of the following is not a part of symplast?

Cell wall
Plasma membrane
Plasmodesmata
Cytoplasm
Symplast is a connection between two cells, which involves, cytoplasm cell membrane and plasmodesmate and not have cell wall in direct contact

13.The first process by which water enters into the seed coat when a seed is placed in suitable environment for germination is

Osmosis
Active transport
Absorption
Imbibitions
Water is absorbed by germinating seeds through the process of imbibitions and helps in rupturing of seed coat. Imbibition is the process of absorption of water by hydrophilic surface of a substance without forming a solution. It is a type of diffusion by which movement of water takes place along a diffusion gradient. During the process of imbibitions, volume of imbibant is changed, heat is produced and imbibitional pressure is developed.

14.In a fully turgid cell, ___ is zero.

OP
TP
WP
DPD
The difference between the diffusion pressure of the solution and its solvents at a particular temperature and atmospheric conditions is called DPD (Diffusion Pressure Deficit). DPD is also known as suction pressure.
In fully turgid cells, turgor pressure is equal to osmotic pressure and hence diffusion pressure deficit becomes zero in such case.
OP=TP(in turgid cell)
∴ DPD= 0(zero)

15.Water potential gradient can be best defined as

Pressure gradient minus water potential
The overall movement of water
Evaporation of water from stem and leaves
The overall movement of solutes
Water potential is a concept fundamental to understanding water movement. Solute potential and pressure potential are two main components that determine water potential

16.Read the following statement carefully and choose the right answer from the codes given below
I. PMA and silicon oil of low viscosity are considered as antitranspirant
II. BAP, NAA and cobalt chloride is also used as antitranspirant
III. Abscisic acid affects the mechanism of opening and closing of stomata
IV. Starch of guard cells is converted into PEP ions by the process of hydrolysis
V. Potometer works on the principle of potential difference between the tip of the tube and that of plant
VI. Transpiration rate is directly proportional to the relative humidity

I, II, III, IV, V and VI
I, II, III and IV are correct while V and IV are incorrect
V and VI are correct, while, I, VI, III and IV are incorrect
I, III, VI are correct, while II, IV, V are correct
Potometer is used to measure the rate of transpiration and it works on the principle that the amount of water absorbed is equals the amount of water transpired. Transpiration rate is inversely proportional to the relative humidity, i.e., rate to transpiration is lower in higher relative humidity while lower humidity (dry air) increases the rate of transpiration

17.When a plant cell is placed in pure water, it

Expands until the osmotic pressure reaches that of water
Becomes less turgid until the osmotic potential reaches that of pure water
Becomes more turgid until the pressure potential of cell reaches its osmotic potential
Becomes more turgid until the osmotic potential reaches that of pure water
When a plant is placed in pure water, the water will move into the cell until the pressure potential and osmotic potential of the cell become equal

18.Which of the following affect the transport of molecules when carrier mediated facilitated diffusion is involved?

Solubility of molecule in lipids
Concentration gradient
Availability of carrier molecule
All of the above
In facilitated diffusion, the rate of diffusion is affected by the solubility of molecules in lipids, concentration gradients, molecular size of the molecules, etc. Availability of carrier molecules also affects the rate of diffusion in facilitated transport

19.Root endodermis has the ability to actively transport ions _A_ because of _B_.
Choose the correct pair

A-bidirectionally; B-plasmodesmata
A-undirectionally; B-casparion strips
A-undirectionally; B-plasmalemma
A-bidrectionally; B-casparion strips
A-unidirectionally, B-casparian strips

20.Which of the following maintains the shape of cell?

Osmotic pressure
Turgor pressure
Wall pressure
Osmosis
The pressure exerted by the protoplasm against the cell wall is called turgor pressure. Turgor pressure maintains the shape of a cell

21.A red blood cell (RBC) was kept in a certain solution for few minutes and it got burst. The said solution was

Isotonic
Concentrated sugar solution
Hypertonic
Hypotonic
When an RBC is kept in hypotonic solution then, water enters the RBC by the process of osmosis (endosmosis). The RBC will increase in size and ultimately burst. Osmosis is the movement of solvent particles from hypotonic to hypertonic medium through semi-permeable membrane.

22.During water absorption from the soil, the water potential of the root cell is __.than the soil

Higher
Lower
Slightly higher
Slightly lower
Water movement between the two system takes place from the system having higher water potential or more energy to the system containing lower water potential or low energy. So, during water absorption from the soil, the water potential of the root cells is lower than that of the soil

23.Which of the following experiments is called physiological demonstration of osmosis?

Thistle funnel, whose mouth is tied with egg membrane
Thistle funnel, whose mouth is tied with parchment paper
Photometer
Bell jar experiment

24.Who proposed the ‘Cohesion Theory’ of ascent of sap?

Strasburger
Godlewski
Western
Dixon andJolly
Cohesion theory or transpiration pull theory for the ascent of sap in plants, was given by Dixon and Jolly (1894).

25.The water available to plants for absorption is

Gravitational water
Hygroscopic water
Capillary water
Chemically bound water
Capillary water is the water present in narrow spaces or microspores of the soil. It is held in the soil by capillary force and therefore, does not fall down to water level. Capillary water is absorbed by plant roots.

26.The space between the plasma membrane and the cell wall of a plasmolyzed cell surrounded by a hypertonic solution is occupied by the

Hypotonic solution
Isotonic solution
Hypertonic solution
Water
When a cell is placed in hypertonic solution, the protoplasm shrinks and leaves the cell wall due to exosmosis and cell becomes failed. The space between plasma membrane and cell wall of plasmolyzed cell is occupied by hypertonic solution.

27.Which of the following has maximum water potential?

Pure water
2% sucrose solution
4% glucose solution
10% sodium chloride solution
Water potential is the difference in free energy or chemical potential per unit molal volume of water in a system and that of pure water at the same temperature and pressure. The water potential of pure water is zero and it decreases on addition of solutes.

28.Which one of the following acts as a barrier in a apoplastic pathway?

Epidermis
Plasmodesmata
Casparian strips
Metaxylem
Water molecules in apoplast pathway are unable to penetrate the layer/bond of suberised matrix called the casparian strip

29.Regarding root pressure, which one is not correct?

It is sufficient to rise water above ground level
It is positive in all except the tallest trees
It do not act as driving force for the mass flow of sugar
It is not able to push water up to small height in the stem
Root pressure, a manifestation of active water absorption is a positive pressure, which develops in the sap of xylem of root of the same plant. It is observed maximum in rainy season in tropical plants and during spring in temperate plants. It is commonly met in plants at around 1-2 atm. It is absent in gymnosperms. Normally observed value of root pressure is not able to raise the level of sap to the top of tree and is only able to raise water level upto or above ground

30.Which of the following is appropriate for mass-flow hypothesis?

Transpiration pull is responsible for absorption of ions
Large amount of ions are also absorbed along with the absorption of water
As suction pressure increases, absorption of water increases and along with water, absorption of ion also increases
All of the above
According to mass-flow hypothesis, there is a mass flow of mineral ions into the root along with transpiration current. Actually, transpiration creates a suction pressure or transpiration pull, conveyed from leaf xylem to root hair, which causes absorption of water from the soil passively. A large amount of ions are also absorbed along with the absorption of water. When the rate of transpiration is high, absorption of water increases due to increased suction pressure and along with water, absorption of ions also increases.

31.Why the tropical deciduous forest trees shed their leaves?

To save energy
To protect itself from chat
To enhance rate of respiration
To prevent loss of water
To prevent loss of water, tropical deciduous forest trees shed their leaves.

32.During flowering, fruit ripening and development period in plants, which part of the plant act as source?

Whole plant
Stem and leaves and the plant
Photosynthesising leaves and older leaves
Growing parts of the plants
The relationship between the source and sink is variable and depends upon season or need of plant. In early spring season, roots act as source, while the buds of plant begin to behave like utilisation site.
Similarly, during flowering and fruit ripening, the flowers and fruits acts like sink region and their source or supply of organic nutrient is completed from the site or photosynthesis, which are green young and older leaves of plants

33.Which part of root absorbs both water and minerals?

Zone of cell differentiation
Zone of cell formation
Zone of cell elongation
Terminal portion of root
In plants, water and minerals both are absorbed by the root hairs. Root hair zone is also known as zone of maturation or differentiation as the cells of this zone undergo maturation and differentiation into different types of primary tissues of the root.

34.Which theory is considered best to explain ascent of sap

Bulk flow system
Transpiration pull
Transpiration
Root pressure theory
Excessive loss of water from the aerial parts of plants causes a tension in whole water column of the plant. As this tension develops due to transpiration, it is also called as transpirational pull. Transpirational pull is also called as cohesion-theory. This theory was proposed by Dixon and Jolly and at present it is most acceptable theory for ascent of sap

35.Which of the following pair is selective and specific mode of transport?

Passive transport and active transport
Passive transport and facilitated diffusion
Facilitated diffusion and active transport
Simple diffusion and facilitated diffusion
Facilitated diffusion and active transport are two important processes of movement of substances, into and out of the cells. These two processes are selective and specific i.e., cells are allowed to select the uptake substances (facilitated diffusion) while active transport is highly specific due to the expenditure of energy

Section-B

36.Movement of Solute molecules from higher concentration to lower concentration without SPM, Channels and Energy is

Diffusion
Osmosis
Active Transport
Facilitated transport
Diffusion is the movement of Solute molecules from higher concentration to lower concentration without utilising energy and membrane channels
Osmosis is the movement of solvent molecules from higher concentration to lower concentration across a semipermeable membrane (SPM)
Facilitated transport requires membrane channels to transport molecules along the concentration gradient and doesn't require energy
Active transport requires energy to move molecules across the membranes

37.Which of the following is not a purpose of transpiration?

Supplies water for photosynthesis
Helps in translocation of sugars from source to sink
Maintains shape and structure of the plant
Cools leaf surface

38.Which statement can be shared by facilitated diffusion and active transport?

Both need carrier transporter, which are sensitive to inhibitors that reacts with protein side chains
Energy is required by both the processes
No energy expenditure in these processes
Both use carbohydrates to move molecules across the membrane
In both, facilitated diffusion and active transport, there is an involvement of carrier transporter or transporter proteins. These are highly specific enzymes and shows sensitivity to inhibitors

39.Stomatal opening is affected by

Nitrogen concentration, carbon dioxide concentration and light
Carbon dioxide concentration, temperature and light
Nitrogen concentration, light and temperature
Carbon dioxide concentration, nitrogen concentration and temperature
Carbon dioxide is an effective antitranspirant. A little rise in $CO_2$ concentration induces partial closure of stomata. It higher concentration results in complete closure of stomata. Light affects the rate of transpiration in two ways-firstly by controlling the stomatal opening and secondly by affecting the temperature. Increase in temperature increases the rate of transpiration.

40.What will be the effect of accumulation of $K^+$ ions in guard cells?

Water potential increases
Water potential decreases
Loss of turgidity
Exosmosis
$K^+$ ions regulate the opening and closing of stomata. Increased concentration $K^+$ and malate ions in the guard cells increases the OP of guard cells, which results in decrease of water potential. Due to which water enters from adjoining subsidiary cells into guard cells by endosmosis. Turgor pressure of guard cells increases, which results in the opening of stomata.

41.If sugars are actively moving into a cell, what will happens to the turgor pressure of the cell?

TP increases, due to the entry of water
TP decreases because water exits
TP increases as sugar concentration affects it directly
No effect of sugar concentration of furgidity hence no change
When a cell is placed in hypertonic solution, the protoplasm shrinks and leaves the cell wall due to exosmosis and cell becomes flaccid. The space between the plasma membrane and cell wall of plasmolysed cell is occupied by hypertonic water

42.Transpiration facilitates

Electrolyte balance
Opening of stomata
Absorption of water by roots
Exertion of minerals
Water rises beyond the point at which it would be supported by air pressure because evaporation from the plant leaves (transpiration) produces a force that pulls upward on the entire column of water. The forces of adhesion and cohesion maintain an unbroken column of water. Thus, transpiration facilitates absorption of water by roots.

43.The rate of diffusion of any substance is not affected by

Electrical charges of diffusing substances
Presence of other substances in the solution
Molecular size of substances in a solution
Solubility to diffusing substance in lipids
In the process of diffusion, electrical charges of diffusing substances, i.e., +ve charge, affects the rate of diffusion. Channel protein allows diffusion of solute or substance of appropriate size, i.e., rate of diffusion also affected by molecular size of diffused materials and solubility of diffusing substances. In lipids these is another factor that affects the rate of diffusion

44.If water enters in a cell, the pressure exerted by its swollen protoplast is

Turgor pressure
DPD
Osmotic pressure
Imbibition
The turgidity of cell increases, if water enters in a cell. As a result of turgidity, turgor pressure is exerted by its swollen protoplast

45.Attraction of water molecules to polar surfaces is known as

Cohension
Capillarity
Surface tension
Adhesion
Adhesion is the attraction of unlike molecules to each other, such as that between water and the walls of xylem vessels in plants.

46.Which of the following lacks stomata?

Aquatic plants with floating leaves
Xerophytes
Aquatic submerged plants
Sciophytes
Transpiration is the loss of water from the aerial part of a living plant. Transpiration may be stomatal (90%), cuticular (3-9%) and lenticular (0.1%). Transpiration is absent in submerged, hydrophytes due to the absence of stomata in the leaves of submerged plant, i.e., potamogeton

47.Carrier protein, which allows the movement of molecules in opposite direction is

Antiport
Symport
Both Antiport and Symport
Uniport
Co-transport is a method of transport in which two types of molecule are transported together. It is of two types, symport method and antiport method. In antiport method, the molecules are transported in opposite direction

48.Transport of organic solutes is supposed to take place by pressure flow hypothesis through phloem tissue from source to sink. Choose the false statement about vascular tissue transport

Phloem transport mainly water and sucrose but other sugars, hormone and aminoacids are also transported
Water enters into the sieve tube by the process of osmosis
Water and solute move through the sieve tube along the pressure gradient
Sieve tube in the source have a low turgor pressure (pressure potential)
Translocation of organic nutrients by phloem can be explained accurately by pressure flow model of Munch. According to the model, the source region always shows higher osmotic concentration. Sieve tube with loaded organic food absorb water from nearby xylem and develop a higher turgor pressure. Movement of organic food occur from an area of higher turgor pressure to a region of lower turgor pressure

49.Which of the following does not affect water potential of water?

Concentration of dissolved substances
Atmospheric pressure
Gravitation
Capillarity
Water potential is the difference between free energy of water molecules in pure form and energy of water in the solution. Water potential depends on solute concentration, atmospheric pressure.

50.Some cells are placed in a solution of glucose to measure the rate of diffusion. As the concentration of glucose solution is being increased, the diffusion rate increases simultaneously. However, when the concentration of glucose solution reaches above 10 m, the diffusion rate no longer increases
Which statement best define the mechanism of glucoses transport in the cells?

Transport of hydrophilic substances along the concentration gradient through fixed membrane transport protein without the involvement of energy expenditure
Transport of hydrophilic substances along and against the concentration gradient via carrier proteins
Active transport via transporter proteins
Facilitated diffusion without carrier proteins
Diffusion is process in which uncharged molecules pass easily through a biological membrane. However, water soluble substance face difficulty to cross the membrane and the transport of these hydrophilic molecules are facilitated by carrier proteins, which are possessed by cell membrane. The overall process do not require energy and is referred to as facilitated diffusion