This question was quite popular among candidates. The candidates that attempted this question scored some good marks because some of them could define ecological niche and state the role of a mango tree in its ecological niche. The candidates that performed poorly lost marks to their inability to state the role of a mango tree in its ecological niche.

Only a few candidates could explain the reason why ecologists use sampling techniques in population studies and name examples of sampling techniques in population studies.

Some candidates could not name the types of fingerprints.

Some candidates that could name the plant used by Gregor Mendel in his experiment could not spell correctly and hence, lost marks.

Only a few candidates could state the reasons why the plant was used in his experiment.

The expected answers are:

(a)  (i) Ecological niche
Where an organism normally lives; and the role it plays in an ecosystem/community.  

(ii) Roles of a mango tree in its ecological niche

• absorbs sunlight for photosynthesis;
• absorbs water/mineral salts from the soil;
• provides shelter for animals/other plants;
• acts as support for creepers;
• produces fruits/food/serves as food;
• serves as fuel source for animals;
• covers the ground with dead leaves that enrich the soil.

                                                                                                     
(b)  (i) Reasons ecologists use sampling techniques in population studies

• Counting individuals could be impossible/difficult in fast moving animals;
• Counting individuals could be tedious;
• Counting individuals could be time consuming/use of technique saves time;
• The terrain/habitat could be difficult to reach.

                                                                                         

(ii) Examples of sampling techniques used in population studies

• Quadrat method;                           -       Random sampling method;
• Line transect method;                   -       Systematic sampling method;
• Sweep net method;                       -       Convenience sampling;
• Pitfall trap method;                       -       Cluster sampling;
• Tullgren funnel method;               -       Stratified sampling;
• Light trap method.

                                                     
(c) Types of fingerprints

• Arch/tented arch;
• Loops/double/central pocket/ulna/radial loop;
• Whorls/accidental/plain whorl;
• Compound.

Note: Spellings must be correct to score.                                       

(d) (i) Plant used by Gregor Mendel
Pea plant/Garden pea plant/Pisum sativum.

(ii) Reasons why the plant was used

• It is self-pollinated/flowers are bisexual;
• Has a short life cycle;
• Produces many offspring in one cross;
• Presence of distinct physical characters that are easily recognizable.