K.C.S.E Biology Q & A - MODEL 2003PP1QN15

K.C.S.E Biology Q & A - MODEL 2003PP1QN15

 A response exhibited by a certain plant tendril is illustrated below.

​a) i) Name the type of response
ii) Explain how the response named in (a)(i) above occurs
b) What is the importance of tactic responses to microscopic plants?
c) State four applications of plant hormones in agriculture.

answers

a) i) Thigmotropism / haptotropism
ii) Contact with support; causes migration of auxine to enter the side; causing faster growth on the side away from centre of surface (causing tendrils curl around support.)
 b) Escape injurious stimuli / seek favorable habitats; move towards light / stimuli.
c) Induce foot growth in stem cutting

• Selective weed killers
• Encourage apical dominance
• Encourage sprouting of side brances
• Breaking seeds dormancy
• Induce pathencarpy
• Promotes flowering
• Induce fruit fall
• Accelerates ripening of fruits.