K.C.S.E Biology Q & A - MODEL 2017PP2QN07

K.C.S.E Biology Q & A - MODEL 2017PP2QN07

Explain the importance of protecting the forest ecosystem with reference to the following: 
(a) climate change
(b) biodiversity
(c) biotechnology
(d) water conservation
(e) pollution.

answers

 a) Climate change

•  Promote(regular) rainfall/precipitation/prevent desertification;
•  Act as wind breakers;
•  Keep earth temperatures cool/reduce global warming;
•  Keeps biogeochemical cycles going e.g. hydrological, carbon,nitrogen, phosphorous, sulphur cycles;

b) Biodiversity

•  Conserve diverse flora/ fauna;
•  Conserve genetic variety;
•  Prevent extinction of rare species;
•  Source of research/employment;
• Aesthetic/attracting tourism in foreign exchange;
•  Have impact on culture/religion/politics;  ‘
•  Food and shelter for other organisms and man;
•  Source of oxygen;

c) Biotechnology

•  Manufacture of medicines/directly used as medicinal;
•  Source of food/food products;
•  Provide fuel (when regulated);
•  Provide paper and related by-products (when regulated);
•  Provide timber (when regulated);
•  Products used in other industries e.g. tannin, wax, rubber, oil, honey;

d) Water conservation

•  Increased ground water/high water tables;
•  Adds into rivers/lakes/permanency ¡n existing water bodies/reservoirs;
•  Water towers/water catchment;

e) Pollution .

•  Minimize soil pollution/ensuring cover against surface run-off/wind erosion/denudation;
•  Trees/vegetation clean the soil surface by absorbing nutrients from decomposed matter e.g. sewage;
•  Large scale clean-up of polluted air/dust;
•  Muffle noise pollution;