Theory question 101
Habitats and Biomes(a) List five morphological features that are characteristic of plants found in each of the following habitats: (i) tropical rainforest (ii) savanna. In each case, state function of the features listed in "a" to the plant
(b) Explain the term: ecological succession
(c) By means of a diagram only, outline the carbon cycle to show the relative importance of the cycle to life in general.
Show the model answer
(a)(i) Rainforest (any five, each with function): tall straight trunks – reach light above other plants; buttress roots – support tall trees in shallow soil; broad thin leaves – trap light in shade; drip tips – shed rain water quickly; thin smooth bark – no need to resist fire/drought; climbers and epiphytes – reach light
(ii) Savanna (any five): thick corky bark – protects against fire; deep/long roots – reach water in the dry season; small or few leaves, leaf shedding – reduce water loss; underground stems/perennating organs – survive fire and drought; tufted grasses – protect buds; short twisted trees – resist wind/fire
(b) Ecological succession: the gradual, orderly change in the plant and animal communities of an area, one community replacing another, until a stable climax community is reached; primary (bare land) or secondary (after disturbance)
(c) Labelled diagram: atmospheric CO₂ → photosynthesis → green plants → eaten by animals; plant and animal respiration return CO₂; death → decay/putrefaction by decomposers returns CO₂; fossilisation → coal, oil, gas → combustion returns CO₂
In (c) every arrow must be labelled with the process, and the answer must be a diagram only.