Which of the following helps in the opening of stomata? (a) Cobalt ions (b) Potassium ions (c) Magnesium ions (d) Aluminium ions

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

Write any two limitations of using a Ganong's Potometer to demonstrate the uptake of water.

Name the following: (i) The organelle that forms the aster during cell division. (ii) A genetic disorder in which the blood does not clot. (iii) The permanent stoppage of menstruation in human females around the age of 45 years. (iv) The openings on the barks of trees through which transpiration occurs. (v) A gaseous plant hormone which promotes ripening of fruits.

Where are Hydathodes located?

Define the term Transpiration.

The paper used to demonstrate unequal transpiration in a dicot leaf is: (a) Filter paper (b) Litmus paper (c) Starch paper (d) Cobalt chloride paper

Given below is a picture of a tree. Mention the scientific phenomena occurring in the parts labelled (a), (b) and (c).

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

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.

Leaves of certain plants roll up on a hot sunny day. Explain by giving suitable reasons.

State any two adaptations in plants to reduce transpiration.