Biology Test
Chapter Transpiration
Full Marks 25. Time 45min
1.Name the following: (5×1=5)(a) openings on the stem through which transpiration occurs
(b) The process by which the intact plant loses water in the form of droplets.
(c) An instrument used to find the rate of transpiration
(d) A plant in which the stomata are sunken
(e) The apparatus to record the rate of transpiration in a cut shoot.
2.Give suitable explanation for the following: (5x1=5)
a) A higher rate of transpiration is recorded on a windy day rather than on a calm day.
b) Excessive transpiration results in the wilting of the leaves.
c) Water transpired is the water absorbed.
d) More transpiration occurs from the lower surface of a dorsiventral leaf.
e) Cork and bark of trees help in preventing loss of water.
3.Answers the following:(3×3=6)
1.There is a general belief that forests tend to bring more frequent rains. Can you explain it scientifically?
2.Mention any three methods by which the plants tend to reduce transpiration ?
3.List any three major factors that accelerate the rate of transpiration?
4.Fill in the blanks:(3x1=3)
(a) Transpiration is the loss of water as water …………… from the ………… parts of the plant.
(b) Closing of …………… and shedding of leaves reduce …………..
(c) Transpiration helps in creating ………………. Force and in eliminating excess………….
5.In an experiment, four freshly plucked leaves (A-D) of a plant, such as those of china – rose, were treated as follows:
(a) Coated with Vaseline on its upper surface.
(b) coated on the lower surface.
(c) coated on both surface .
(d) left uncoated. All the four leaves A, B, C & D were left in a room for about 24 hours.
(i) which leaf would become most limp? Why?
(ii) which leaf would show least limping? Why?
(6 marks)