This was also a popular question among the candidates. Majority of the candidates could define pollution and name water pollutants correctly with perfect spellings.
Many candidates could define population correctly but could not describe the use of pitfall trap and were instead treating it as a quadrat
Expected answers include:
(b) Use of a pitfall trap in sampling organisms
It consists of
- a large jar with straight sides buried in a hole in the soil; with the mouth upwards;
- food as bait is put into the trap/large jar;
- the traps are placed randomly within the habitat;
- and examined regularly/at intervals;
- organisms lured by the bait; fall into the trap;
- the organisms captured are collected;
- identified;
- counted;
- released.
