15919.When a plant is girdled (ringed)
the root and shoot die at the same time
the shoot dies first
the root dies first
neither root nor shoot will die
15920.In a plant organ, which is covered by periderm and the stomata are absent, some gaseous exchange still takes place through
pneumatophores
trichomes
aerenchyma
lenticels
15921.The relationship among different types of soil water can be summed up by the following equation:
Echard = Hollard + Chresard
Chresard = Hollard – Echard
Chresard = Echard + Hollard
Hollard = Chresard – Echard
15922.Water will be absorbed by root hair when
concentration of salts in the soil is high
concentration of solutes in the cell sap is high
plant is rapidly respiring
they are separated from soil by a permeable membrane
15923.
Select the correct events leading to the opening of the stomata
a. Decline in guard cell solutes
b. Lowering of osmotic potential of guard cells
c. Rise in potassium levels in guard cells
d. Movement of water from neighbouring cells into guard cells
e. Guard cells becoming flaccid
a, c and d only
b, c and d only
a and e only
b, d and e only
15924.Water is lost in a liquid state in some plants through hydathodes. These hydathodes
do not show any specificity in opening and closing
remain closed during day
remain closed at night
remain always open
15925.Passive absorption of water by the root system is the result of
Tension on the cell sap due to transpiration
Increased respiratory activity in root cells
Forces created in the cells of the root
Osmotic force in the shoot system
15926.
Study the following table:
(I) Peperomia - Leaf succulent - Leaf epidermal cells store water
(II) Calotropis - Non-succulent - Root cells with thickened cell walls
(III) Tribulus - Ephemeral - Stem stores water
(IV) Ammophila - Dicot plant - Rolling in of leaves to check water loss
Identify the correct pair of answers.
I, II
I, III
II, III
II, IV
15927.In which of the following plants, there will be no transpiration?
Plants growing in hilly regions
Aquatic, submerged plants
Plants living in deserts
Aquatic plants with floating leaves
15928.A leaf peeling of Tradescantia is kept in a medium having 10% NaCl. After a few minutes if we observe the leaf peel under the microscope, we are likely to see
Entry of water into the cell
Exit of water from the cell
Diffusion of NaCl into the cell
The cells bursting out
16393.Which one of the following is used for measuring the rate of transpiration?
Ganong's potometer
Moll's experiment
Auxanometer
Respirometer
16394.The existence of root pressure can be demonstrated by
Exudation or bleeding
Wilting
Transpiration
Bleeding
16396."Pulsation theory" to explain ascent of sap was proposed by
Dixon and Jolly
J .C. Bose
Curtis and Clark
None of the above.
16397.A cell placed in hypertonic solution plasmolysis; the space between the cell wall and plasmolysed contents is filled with
Water
Cell sap
Hypertonic solution
Hypotonic solution
16398.Of the processes which occur in leaves, the one which may lower their temperature (cooling effect) is
respiration
Photosynthesis
Transpiration
hydrolysis
16400.A cell becomes turgid when placed in
Isotonic solution
Hypertonic solution
Hypotonic solution
All of these
16401.A cell when placed in solution gets plasmolysed. What is largely present in between the cell wall and the plasmolysed contents?
Water
Cell sap
Hypotonic solution
Hypertonic solution
16402.A small mesophytic twig with green leaves is dipped into water in a big beaker under sunlight. It demonstrates
Photosynthesis
Respiration
Transpiration
None of these
16403.A thin film of water is held by the soil particle under the influence of internal attractive force. It is called
Capillary water
Combined water
Hygroscopic water
Gravitational water
16404.When a cell is fully turgid, which one of the following is zero?
Turgor pressure
Wall pressure
Diffusion pressure deficit
Osmotic pressure
16405.Active K+ exchange mechanism for the opening and closing of stomata was given by
Devlin
Levitt
Seath
Khorana
16406.The plants die due to wilting when
available light is reduced to half
xylem is blocked
a few roots are broken
phloem is blocked
16407.After heavy rain fall with poor drainage, leaves of many plants wilt due to
Root rot
Poor soil aeration
High salt concentration
Low soil temperature
16408.The direction and the rate of water movement from cell to cell is based on
Diffusion pressure deficit
Incipient plasmolysis
Turgor pressure
Wall pressure
16409.At very low temperature, plants do not grow. This is due to
Desiccation of plants
Solarisation of plants
Cell cannot grow
Cell wall will be inhibited
16410.Which one of the following is produced during water stress and causes closure of stomata?
Auxin
Abscisic acid
Cytokinin
Gibberellin
16412.Conversion of starch to organic acid is essential for stomatal
closure
opening
initiation
growth
16413.Dixon and Jolly are associated with
Light reaction of photosynthesis
Anaerobic respiration
Cohesion theory of Ascent of sap
Apical dominance
16415.During absorption of water by roots, the water potential of cell sap is lower than that of
pure water and soil solution
neither pure water nor soil solution
pure water, but higher than that of soil solution
soil solution, but higher than that of pure water
16417.Stomata of a plant open due to
influx of potassium ions
Efflux of potassium ions
Influx of hydrogen ions
Influx of calcium ions
16418.Field capacity is
Higher for sandy soils than clay soils
Amount of water in soil available to plants
Same as permanent wilting point
Amount of water left in soil after drainage
16419.Transpiration is helpful to plants in
Cooling
loss of excess nutrients
upward conduction/ascent of sap
loss of excess water
16420.The chief water conducting elements of xylem in gymnosperms are
Tracheids
Vessels
Fibers
Transfusion tissue
16421.Increase in the CO2 concentration of micro environment of leaf would cause
closure of stomata
opening of stomata
no effect on stomata
widening of stomata
16422.Flooding kills plants because
Cell sap in plants become too dilute
Root respiration ceases
Cell sap in plants become too dilute
Excess water Ieaches down plant nutrients.
16424.If CO2 concentration suddenly increases around the leaf, one of the following events occurs
Stomata open gradually
Stomata open suddenly
Transpiration will not be affected
Decrease in transpiration due to sudden closure of stomata
16425.The cells which are closely associated and intercating with guard cells are
Transfussion tissue
Complementary cells
Subsidiary cells
Hypodermal cells
16426.If the concentration of external solution is more than the cytoplasm, the solution is known as
Hypertonic
Isotonic
Hypotonic
None of these
16427.The part of Root involved in water absorption is
Zone of cell division
Zone of root hairs
Zone of elongation
Zone of root cap
16429.When water enters the cell, one of the pressures is exerted on cell wall
Osmotic pressure
Sunaction pressure
Turgor pressure
Root pressure
16430.Transplanted plant sometimes do not survive as
They do not get required minerals
Their leaves get damaged in the process
Their root hairs are lost during transplanatation
They fails to adopt new soil
16431.Diffusion of water through semipermeable membrane from dilute solution to concentrated solution is
Imbibition
Osmosis
Plasmolysis
Necrosis