- Which of the following is used to determine the rate of
transpiration in plants?
(a) Porometer (b) Potometer
(c) Auxanometer (d) Tensiometer
- Water drops present on leaf margins of Tropaeolum, Balsam
and grasses in early morning are due to
(a) bleeding (b) high root pressure
(c) osmosis (d) transpiration.
- In which of the following plants would metabolism be hindered if
the leaves are coated with wax on their upper surface?
(a) Hydrilla (b) Lotus (c) Potamogeton (d) Vallisneria
- Transpiration is least at
(a) good soil moisture
(b) high wind velocity during storm like condition
(c) dry environment (d) afternoon.
- In soil, the water available for absorption through root is
(a) gravitational water (b) capillary water
(c) hygroscopic water (d) combined water.
- Supply of excess fertiliser and watering of a grass lawn causes
browning of grass leaves due to
(a) decreased photosynthesis
(b) water logging of soil
(c) leaching of fertiliser to lower soil strata
(d) exosmosis and death of root.
- During absorption of water by roots, the water potential of cell
sap is lower than that of
(a) pure water and soil solution
(b) neither pure water nor soil solution
(c) pure water but higher than that of soil solution
(d) soil solution but higher than that of pure water.
- A twig dipped in water, having small amount of salt, from its
cut end remains fresh for longer period due to
(a) decrease in bacterial degradation
(b) exosmosis
(c) decrease in photosynthetic rate
(d) absorption of more water.
- Potato slices were placed in sucrose solution. After half an hour,
density of sucrose solution increased. Water potential of potato
tuber is
(a) equal to solute potential of sucrose solution
(b) greater than solute potential of sucrose solution
(c) less than solute potential of sucrose solution
(d) half the concentration of sucrose solution.
- Match column I with column II and select the correct option
from codes given below.
Column I Column II
A. Girdling (i) Demonstrate transpiration
experiment pull
B. Cobalt chloride test (ii) Transpiration
C. Atmometer (iii) Use to compare transpiration
from two surfaces
D. Bell jar experiment (iv) Translocation in phloem
(a) A-(iv), B-(i), C-(ii), D-(iii)
(b) A-(iv), B-(iii), C-(i), D-(ii)
(c) A-(ii), B-(i), C-(iv), D-(iii)
(d) A-(iii), B-(i), C-(iv), D-(ii)
- Main function of lenticels and stomata is
(a) transpiration (b) guttation
(c) gaseous exchange (d) both (a) and (b).
- Choose the correct sequence of events during wilting.
(a) Exosmosis, deplasmolysis, temporary wilting, permanent
wilting
(b) Exosmosis, plasmolysis, temporary wilting, permanent
wilting
(c) Endosmosis, plasmolysis, temporary wilting, permanent
wilting
(d) Exosmosis, temporary wilting, deplasmolysis, permanent
wilting
- Osmotic pressure of a solution is
(a) more than that of pure solvent
(b) less than that of pure solvent
(c) equal to that of pure solvent
(d) none of these.
- Sunken stomata occur in the leaves of
(a) Cycas (b) Nerium (c) Pinus (d) all of these.
- Which one is responsible for opening of stomata?
(a) Decrease in CO 2 concentration and increase in H+ ion
concentration
(b) Decrease in CO 2 concentration and decrease in H+ ion
concentration
(c) Increase in CO 2 concentration and increase in H+ ion
concentration
(d) More free H+ ions and less Cl– ions
- A cell is said to be flaccid when
(a) it has no water in vacuole
(b) TP = OP (c) DPD is strongly –ve
(d) water flow into the cell and out of the cell is in equilibrium.
- Which of the following statement is true regarding <w?
(a) <w = 0, if pure water is applied with pressure of 100 bars.
(b) <w = <s + <p for a partially turgid cell.
(c) <w = <s for a fully turgid cell.
(d) <w = <s - <p when cell is fully flaccid.
- S symbol is used to denote
(a) turgor pressure (b) osmotic pressure
(c) diffusion pressure deficit (d) osmotic potential.
- Select the correct event leading to stomatal opening.
(i) Decline in solutes in guard cells
(ii) Increased wall pressure of guard cells
(iii) Rise in K+ ions in guard cells
(iv) Movement of water from neighbouring cells into guard cells
(v) Guard cells become flaccid.
(a) (i) and (v) only (b) (ii), (iii) and (iv) only
(c) (i), (iii) and (iv) only (d) (ii), (iv) and (v) only
