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After an ecological study of feeding relationships, student constructed the food web below.

(a) Name the process through which energy from the sun is incorporated into the food web.
(b) State the mode of feeding of the birds in the food web.
(c) Name two ecosystems in which the organisms in the food web live.
(d) From the information in the food web, construct
a food chain with the large bird as a quarternary consumer.
(e) What would happen to the organisms in the food web if bird N migrated?
(f) Not all the energy from one trophic level is available to the next level. Explain.
(g) (i) Two organisms which play a role in the ecosystems are not included in the food web. Name them.
(ii) State the role played by the organisms named in (g) (i) above.
(h) (i) State three human activities that would affect the ecosystem.

Answer Text:
(a) Photosynthesis
(b) Heterotrophism
(c) - Pond or dam
- Rain forest
(d) Algae#rarr# zoo plankton #rarr# small fish #rarr# birds #rarr# large birds
(e) - Snails would increase in number.
- Bird M would increase in number
- Green plants would decrease in number.
(f) - The energy to be passed on from one trophic level to the next is contained in food materials. Most
of the food taken in by consumers passes through the digestive track as undigested matter that is removed as faces. The digested materials are absorbed into the blood stream and conveyed to
various tissues of the body. Most of the absorbed food materials are used in respiration, to produce
energy.
- Some is lost as heat during sweating ,evaporation and transpiration in plants.
- Not all energy is trapped and passed on to the next level or not all organisms are consumed to give energy.
(g) (i)- Scavengers for example,vultures
- Decomposers for example, saprophytic bacteria and fungi
(ii) - Scavengers feed on dead bodies of herbivores and carnivore/ the consumer.
- Decomposers act upon the remains of the producers and consumers causing decay hence release inorganic materials or nutrients, which are
later re-used by producers to make new organic
compounds that is, they bring about recycling of materials/nutrients in an ecosystem.
(h) (i)- Deforestation
- Overgrazing
- Hunting/poaching/overfishing
- Poor waste disposal/environmental pollution