Page 173 - Biology_F5

Biology for Advanced Level Secondary Schools

capable of fixing atmospheric nitrogen White pines are extensively used for
from the atmosphere into available making boxes, furniture, floor, and
forms, which can be absorbed by plants. panel.

(d) Plants help to conserve water in the soil (k) Resins from pines are used for making
by preventing excessive evaporation. premier paints and varnish, solvents,
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For example, plant leaves and grasses ointments, wax, and shoe polish.
are used as mulching materials covering (l) They provide timber for various
the soil surface to conserve water. purposes such as furniture making,
poles for houses construction and
(e) Grasses and some trees have important electric supply.
catchment value, because they have
matted root networks that reduce lateral (m) Forests attract tourists and thus aid in
flow of water, evaporation, and soil generating national income.
erosion. (n) Plant leaves such as grass, banana and
coconut leaves, are used for thatching
(f) Plant communities or vegetation, such houses.
as grasslands, woodland, and forests
provide habitats for wild animals. (o) Fern rhizome, root bark, and rhizome
Additionally, bird species use plant bark of certain species are used for
materials for construction of their nests. growing Orchids.
(p) Some plants are source of medicine, for
(g) Plants are used in research and example neem trees.
biological studies.

(h) Plants are sources of traditional fuel, Disadvantages of kingdom Plantae
such as charcoal and firewood. In (a) Some plants can produce metabolites
Africa, for instance, approximately or accumulate toxic or poisonous
90% of the population use charcoal as products which are dangerous to
a source of domestic energy.
consumers (animals). Cassava plants
(i) Ferns and most angiospermophytes are can accumulate cyanide, which is
grown as ornamental plants for indoor toxic, when consumed by humans.
and outdoor decoration, examples: true
ferns, Hibiscus, cacti and roses. Jatropha curcas produces a toxic
protein called curcin. Tea and coffee
(j) They provide raw materials for produce caffeine, which in high doses
industrial purposes. Examples are
cotton for making clothes, latex for may cause hypertension in humans.
making rubber, cellulose for making (b) Weed plants compete with food crops,
fiber products such as ropes, and wood leading into low crop yield.
pulp for making paper. Additionally, (c) Some plants are parasites to other
fibres from plants, such as sisal are used plant species. For instance, Cassytha
to manufacture mattresses and carpets. filiformis is a parasitic weed in crops

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