(a) List four floral parts of a flower. (b) (i) In a tabular form, state five differences between wind and insect pollinated flowers. (ii) Give one example ...

Answer Details

(a) Four floral parts of a flower

Sepals (calyx), petals (corolla), stamens (androecium, the male part), and carpels/pistil (gynoecium, the female part).

(b)(i) Differences between wind- and insect-pollinated flowers

(b)(ii) Examples

• Wind-pollinated: maize (also grasses, guinea corn).
• Insect-pollinated: Hibiscus (also flamboyant, Crotalaria).

(c)(i) Three agents of fruit and seed dispersal

Wind, water, animals (and explosive/self mechanism).

(c)(ii) Examples dispersed by each

• Wind: Tridax / cotton seed (light, winged or hairy fruits and seeds).
• Water: coconut (buoyant fruit).
• Animals: Desmodium / cactus (hooked or fleshy fruits); also mango eaten by animals.
• Explosive mechanism: Crotalaria / oil bean (pods that burst open).

(d)(i) Hormones

Hormones are chemical substances produced in small quantities by an organism which are transported to other parts of the body where they control and coordinate growth, development and other activities.

(d)(ii) One plant hormone

Auxin (others: gibberellin, cytokinin, abscisic acid, ethylene/ethene).

(d)(iii) Two effects of plant hormones

• They promote cell elongation and growth of stems and roots (and control tropisms, that is, growth movements towards or away from a stimulus).
• They control the ripening of fruits, formation of fruits, and flowering.
• They control leaf and fruit fall (abscission) and seed/bud dormancy.