Theory question 102
Reproduction in Plants(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 of each
(c) (i) State three agents of fruit and seed dispersal (ii) Give an example of fruits or seeds dispersed by each agent
(d) (i) Define the term 'hormones'. (ii) Name one plant hormone (iii) State two effects of plant hormones.
Show the model answer
(a) Any four: calyx (sepals); corolla (petals); androecium (stamens); gynoecium (pistil/carpels); also receptacle, pedicel, epicalyx.
(b)(i) Wind-pollinated vs insect-pollinated: small, dull flowers vs large, brightly coloured; no scent vs scented; no nectar vs nectar present; large amounts of pollen vs less pollen; light, smooth, dry pollen vs heavy, rough/sticky pollen; large feathery stigmas hanging outside vs small, sticky stigmas inside the flower; long filaments with loosely attached anthers vs short, firm stamens.
(ii) Wind: maize/grass/rice. Insect: pride of Barbados/hibiscus/Delonix.
(c)(i)–(ii) Any three agents with an example: wind – Tridax/cotton/Aspilia; animals – mango/pawpaw/Desmodium (hooks); water – coconut/water lily; explosive (self) mechanism – pride of Barbados/okra/balsam; man – cocoa/oil palm.
(d)(i) Hormones are organic chemical substances made in small amounts in one part of an organism and carried to another part where they bring about a specific effect.
(ii) Auxin (IAA), gibberellin, cytokinin, abscisic acid or ethylene.
(iii) Any two: promote cell elongation/growth; cause tropisms (bending towards light); promote fruit ripening (ethylene); cause seedless fruit (parthenocarpy); cause dormancy or abscission of leaves (abscisic acid); maintain apical dominance; promote rooting of cuttings.
Put the wind/insect differences in matching pairs across a two-column table.