a] Plants do not have any nervous system but yet, if we touch a sensitive plant, some observable changes take place in its leaves. Explain how could this plant respond to the external stimuli and how it is communicated.
b] Name the hormone that needs to be administered to
i] increase the height of a dwarf plant.
ii] cause rapid cell division in fruits and seeds.

Explanation

a] The plant will immediately change the shape by changing the amount of water in them (swelling or shrinking) thus bringing movement.
b] i] Gibberellin/Auxin
ii] Cytokinin