(a) Difference between tropic movement and nastic movement

Tropic movement	Nastic movement
It is a growth movement	not a growth movement
Response to unilateral stimulus	response to diffuse stimulus
Slow response	Fast response
Not reversible	Reversible
Not due to cell tugor	Due to changes in cell tugor
Directional/positive /negative response	positive nor negative response

(b) How light brings about tropic movement in stem and root of a flowering plant:
(i) When unilateral light falls on the stem, the auxin/growth hormone/IAA is displaced from the lighted to the dark side.
(ii) The increase in auxin concentration on the dark side increases growth on that side causing the stem to bend towards the light/positive phototropism.
Roots:
(i) The auxin is displaced from the lighted side to the dark side.
(ii) The increase in auxin concentration retards growth on the dark side causing the root to bend away from the light/negative phototropism.
(c) The following would be observed when a growing seedling is placed horizontally:
(i) Shoot bends upwards, showing negative geotropism/positive phototropism.
(ii) Root bends downwards, showing positive geotropism/negative phototropism.
(d) Functions of the Pituitary gland:
(i) Stimulates growth/growth of long bones/cell division.
(ii) Stimulates production of sex-hormones/named sex hormones.
(iii) Stimulates production of anti-diuretic hormone/ADH/regulation of water re-absorption in the kidney/osmos regulation.
(iv) Produces hormones which control other endocrine glands/stimulates thyroid gland/adrenal cortex.
(v) Stimulates protein synthesis.
(vi) Induces birth by contraction of uterine muscles/production of oxytoxin.
(vii) Induces milk secretion/produces prolactin.
(viii) Controls egg and sperm production.
(e) Differences between growth in plants and animals:

Growth in plants	Growth in animals
Unlimited growth/growth through out life	limited growth/growth stops after a period of time
No fixed number of organs	fixed numbers of organs (e.g two eyes,ears etc)
limited to specific region	not restricted/intercalary