Observation

This was the most popular question among the candidates. Only a few candidates could not explain renewable and non-renewable natural resources and give examples.

In (c), many candidates could not extensively state ways of conserving a forest which made hem lose marks. Some candidates gave conservation of wildlife instead of forest. Some out of carelessness wrote bust for bush burning and five for fire which gave different meanings to their answers.

In (d), many candidates could only state that it improves the quality and fertility of the soil
In (e), candidates were just writing as much genotypes that they think should be the answer. Some even wrote blood groups A, B, O as genotypes, some even wrote blood, intelligence as answer.

The expected answers are:

3. (a) (i) Renewable natural Resources         
Materials that can be reused/replaced/regenerated/recycled; after they have been used.                                                                                       
(ii) Non-renewable natural Resources     
Materials that are difficult/impossible to regenerate/recycled; after being exhausted/depleted.                                                                                                                      
(b)   (i) Renewable natural Resources        
Air; soil; crops; fisheries; water; vegetation/forest; game/wildlife.           

(ii) Non-renewable natural Resources     
Rocks; coal; minerals/correctly named example; crude oil/petroleum.

 

    (c) Ways of conserving forest

• Prevent forest/bushfires;
• Practice selective cutting of trees/avoid indiscriminate felling of trees;
• Regulations/laws to control excessive clearing of forest;
• Practice afforestation/plant new trees;
• Employ forest guards to prevent/arrest intruders;
• Use pesticides to kill pests/control plant diseases;
• Embark on public education on dangers of deforestation.          

    (d) Effects of adding animal manure to garden soil

• Animal manure provides nutrients/nitrogeneous materials/improves soil fertility;
• Animal manure are acted upon by nitrifying bacteria;
• To form nitrates for plants;
• Manure improves the water-holding properties of the soil by binding the soil particles together/improves soil structure;
• Prevents soil from being blown away by wind/erosion.              

   (e) Possible genotypes in humans

AA, AS, SS