Theory question 103
Ecosystem and Ecological Factors(a) Explain briefly the following ecological terms: (i) biosphere; (ii) habitat.
(b) Describe the mode of nutrition in a named carnivorous plant.
(c) State three reasons why the dispersal of fruits and seeds are important.
(d) State six methods of conserving soil.
Show the model answer
(a)(i) Biosphere: the zone of the earth (land, water and lower atmosphere) where living things are found.
(ii) Habitat: the particular place where an organism or a population lives, e.g. a pond or forest floor.
(b) e.g. Sundew (Drosera) or pitcher plant / bladderwort: it grows in nitrogen-poor soil; it makes carbohydrates by photosynthesis; insects are attracted by colour, scent or nectar; they are trapped (sticky glandular hairs fold over them in sundew; slippery walls into a fluid-filled pitcher); glands secrete protein-digesting enzymes; the digested products (amino acids, nitrogen compounds) are absorbed to supply nitrogen.
(c) Any three: prevents overcrowding of seedlings; reduces competition for light, water and nutrients with the parent and each other; allows colonisation of new areas; increases survival of the species; reduces spread of disease.
(d) Any six: crop rotation; cover cropping; mulching; contour ploughing/terracing; planting windbreaks/afforestation; avoiding bush burning; avoiding overgrazing; adding manure/fertilisers; strip cropping; bush fallowing.
In (b) name the plant and say why it traps insects (to get nitrogen).