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Q.
A pair of guard cells form a
AMUAMU 2001
Solution:
Stoma is a pore, which functions in gas exchange between the plant and the atmosphere. Each stoma is bordered by 2 semicircular guard cells, whose movement controls the size of the aperture.
Lenticel is a pore formed as a result of secondary growth in the outermost layer of stem for gaseous exchange.
Hydathode is a pore found in the epidermis of the leaves of certain plants. Hydathodes are used by the plants to secrete water under condition, in which transpiration is inhibited, eg. when the atmosphere is very humid.
Laticifers are the tissue secreting latex (an emulsion of various metabolic products in matrix of watery base). Laticifer consists of thin walled elongated branched ducts.