Candidates did not perform well in this question. Most dodged question (a) while those that attempted it did not correspond the observed traits with the deficient elements. Many candidates also missed vital points in (c). Questions (b) and (d) were well answered.
The expected answers are:
The expected answers are:
Deficient elements in the garden soil
Observed traits |
Deficient elements |
(i) Yellow leaves |
Iron/sulphur/nitrogen/magnesium |
(ii) Stunted growth |
phosphorus/potassium/sulphur/
nitrogen/magnesium/calcium |
(iii) Molting leaves |
phosphorus |
(iv) Weak stem |
calcium/sulphur |
(v) purple colour |
phosphorus |
(vi) Orange colour |
potassium |
Similarities in the alimentary canal of Birds and Cockroach
- Possession of narrow oesophagus;
- Possession of crop;
- Possession of caecum;
- Possession of muscular gizzard;
- Possession of mid-gut/intestine;
- Possession of rectum.
Differences between the alimentary Canal
Bird |
Cockroach |
-mouth is modified into beak for pecking |
mouth modified for chewing and biting; |
- tongue is present in the mouth |
tongue is absent in the mouth; |
- duodenum is present |
duodenum is absent; |
- alimentary canal is long |
alimentary canal is relatively short; |
- hindgut terminates into cloaca |
hindgut terminates into anus; |
- malpighian tubules are not attached
to the alimentary canal |
malpighian tubules are attached to
to the alimentary canal |
- liver/pancreas present in the alimentary
canal |
liver/pancreas absent in the
alimentary canal; |
- salivary gland absent |
salivary gland present. |
Note: Points must correspond to score.