K.C.S.E Biology Q & A - MODEL 2005PP1QN17

K.C.S.E Biology Q & A - MODEL 2005PP1QN17

After an ecological study of feeding relationships students 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 ecosystems. 
ii) Explain how the activities stated in h(i) above would affect the ecosystems.

answers

​a)Photosynthesis
b)Heterotrophic – holozoic
c) Small fish pond / dam, rain forests.
d) Algae Zoo plankton small fish bird    large bird.
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 passed on from one trophic level to the next is consumers passes through the digestive track as undigested matter that is removed as faeces. The digested materials are absorbed in to the bloodstream and conveyed to various tissues of the body. Most of the absorbed food materials are used in respiration, to Produce is lost as heat during sweating, evaporation and transpiration in plants.
g)i) Scavengers e.g. vultures
Decomposers e.g. bacteria
ii) Scavengers feed on dead bodies of herbivores and carnivore / the consumers.
-Decomposers act upon the remains of the producers, consumers, & Scavengers causing decay, to release inorganic materials, which are later re-used by producers to make new organic compounds.
h) i) -Deforestation
  -Overgrazing
   -Soil erosion
   -Hunting, poaching
   -Over fishing
   -Poor waste disposal // Environmental pollution 
 ii) Deforestation
Lack of trees leads to reduced number producers in an ecosystem.
Overgrazing
Many animals eat away and trample the vegetation hence reducing / depleting the number of producers.
-Lead to gully erosion hence carrying away some of the underground and crawling animals (Consumers)