(a) (i) Describe epigeal germination of a seed.
(ii) In a tabular form, state three differences between epige germination and hypogeal germination.
(b)(i) What is seed dormancy?
(ii) State three ways b which dormancy in seeds can be broken.
(c) State six advantages of using contraceptives in puma populations.
Explanation
(a)(i) Description of Epigeal Germination:
(i) Seed absorbs/imbibes water and swells.
(ii) Testa splits and the radicle emerges.
(iii) The hypocotyl of the germinating seed elongates.
(iv) Pushing the seed out of the soil.
(v) The cotyledon(s) become exposed to sunlight.
(vi) Turns green to photosynthesize.
(vii) The plumule develops into a green shoot.
(viii) The cotyledon(s) dry up/shrink and fall off.
(ii) Differences between epigeal and hypogeal germination:
Epigeal germination | Hypogeal germination |
Hypocotyl elongates | Epicotyl elongates |
cotyledon | cotyledon remains in the soil |
cotyledon(s) turns green / photosynthesize | cotyledon does not photosynthesize |
plumule does not emerge simultaneously with the radicle | plumule emerges simultaneously with radicle |
Energy with the radicle from cotyledon | energy derived from endosperm |
(b)(i) Seed dormancy: An inactive period of a seed.. During which growth slows/completely ceases. Due to certain internal or external factors.
(ii) Ways of breaking dormancy: Removal/corrosion of testa. Treatment of seed with acid/digestive enzymes/water. Exposure to alternating high and low temperature. Addition of dormancy-breaking hormones/named hormones. Exposure to fire. Exposure to light.
(c) Advantages of using contraceptives in human population:
(i) It controls birth rate.
(ii) Reduces over-population.
(iii) Promotes maternal health/reduces maternal death.
(iv) Promotes infant survival rate.
(v) Enables parents to determine family size.
(vi) Prevents unwanted pregnancy.
(vii) Enhances good standard of living for the family.
(viii) Some prevent STI or STDs.