Chemical Coordination in Plants — Question 1

(a) Phytohormones — Phytohormones or plant hormones are naturally occurring small organic molecules.

(b) Tropism — Response or orientation of a plant to certain stimulus that acts with greater intensity from one direction to another is called tropism.

(c) Clinostat — Clinostat is a mechanical device that rotates at a slow speed to demonstrate geotropism.

(d) Apical dominance — The phenomenon of the suppression of growth of lateral buds by apical buds is called apical dominance.

(e) Parthenocarpy — Development of fruits without fertilisation is called parthenocarpy.

(f) Abscission — Abscission is the shedding of various parts of a plant such as leaves, buds, flowers and fruits.

(g) Heliotropism — The phenomenon in which the young flower heads follow the sun across the sky as it moves from east to west direction is called heliotropism.