Assertion (A): A thick cuticle reduces transpiration by acting as a barrier.
Reason (R): Desert plants have large, thin leaves for transpiration.
(a) (A) is true and (R) is false
(b) (A) is false and (R) is true
(c) Both (A) and (R) are true and (R) is the correct explanation of (A).
(d) Both (A) and (R) are true and (R) is not the correct explanation of (A).
(a) (A) is true and (R) is false
Explanation: A thick, waxy cuticle reduces water loss from the leaf surface, so the assertion is true. Desert plants usually have small leaves or spines to reduce transpiration; they do not have large, thin leaves for this purpose. Therefore, the reason is false.
More ICSE Moderate level questions
Two well-watered, identical plants were placed in brightly lit rooms at different temperatures — one at 15°C and the other at 38°C. The plant in the warmer room showed wilting by the end of the day. (a) Which plant phenomenon resulted in the wilting of the leaves? (b) Mention the factor of the phenomenon that is being tested.
Write any two limitations of using a Ganong's Potometer to demonstrate the uptake of water.
Read the explanations given below and name the structures: (a) The canal through which the testes descend down into the scrotum just before the birth of a male baby. (b) The part of the brain that regulates the peristaltic movement of the alimentary canal. (c) A structure that collects the soundwaves and conducts them through the external auditory canal. (d) The point of attachment of two chromatids of a chromosome. (e) Regulation of the opening and closing of stomata.
Match the items in Column I with those in Column II: Column I Column II Leydig cells Lack of thyroxine in children Stoma 12 pairs Ova Testosterone Cranial nerve Diffusion of respiratory gases Cretinism Haploid cells 31 pairs Diploid cells
Leaves of certain plants roll up on a hot sunny day. Explain by giving suitable reasons.
Arrange the terms in each group in the correct order. Write them in a logical sequence beginning with the term that is underlined. (a) Palisade cells, Cuticle, Upper epidermis, Spongy cells. (b) Hepatic portal vein, Stomach, Hepatic vein, Liver. (c) Cyton, Dendrites, Synaptic cleft, Axon endings. (d) Insulin release, High blood sugar, Lowers blood sugar, Stimulates glucose uptake from blood. (e) Sperm duct, Seminiferous tubule, Epididymis, Efferent ducts.
Arrange the following in a logical sequence: (a) Australopithecus, Cro-Magnon, Homo erectus, Neanderthal man. (b) Pupil, Aqueous humour, Retina, Vitreous humour. (c) Effector, Receptor, Motor neuron, Sensory neuron. (d) Loop of Henle, Distal convoluted tubule, Bowman’s Capsule, Proximal convoluted tubule. (e) Water vapour, Soil water, Leaves, Ascent of Sap.
State any two adaptations in plants to reduce transpiration.
Name the following: (a) The fully developed part of the ovary containing a mature ovum. (b) A waxy layer on the upper epidermis of leaves meant to reduce Transpiration. (c) The ear ossicle which opens into the oval window of Cochlea. (d) The physiological process which is the starting point of all food chains. (e) An insect which is a classic example of natural selection due to industrial melanism.
Which of the following helps in the opening of stomata? (a) Cobalt ions (b) Potassium ions (c) Magnesium ions (d) Aluminium ions
Where are Hydathodes located?
The process by which water is lost from the margins of the leaves of a strawberry plant is: (a) Osmosis (b) Imbibition (c) Diffusion (d) Guttation
