Question 4
The diagram below illustrates the digestive system of a farm animal. Study it and answer the questions that follow.
(a) Name the parts labelled I, II, III and IV in the diagram. (4 marks)
(b) State one function of each of the parts labelled III, IV, V and VI. (4 marks)
(c) Give four examples of farm animals which possess the digestive system illustrated in the diagram. (4 marks)
(d) Name three viral diseases that affect the farm animals which possess the stomach type illustrated by the diagram.
Observation
Candidates’ performance in Question 4 was above average.(a) Many candidates were able to state the parts of the digestive system of poultry, their functions and examples of farm animals which possess this digestive system.
(c) However, many candidates were unable to name viral diseases which affect poultry.
The expected answers include:
4. (a) Naming of labelled parts
I - Crop
II - Proventriculus/glandular stomach
III - Gizzard
IV - Pancreas
(b) Functions of the labelled parts
III (Gizzard)
- Grinding of feed into a thick paste through the contraction of the muscular
walls
- Mixing of ingesta IV (Pancreas)
- Secretion of pancreatic juice
- Produces insulin which regulates blood sugar V (Caecum)
- Bacterial breakdown of undigested feed VI (Gall bladder)
- Secretion of bile
- Storage of bile
(c) (i)Examples of farm animals possessing the digestive system
- Chicken/domestic fowl
- Duck
- Guinea fowl
- Turkey
- Goose
- Quail
- Ostrich
(d) Viral diseases that affect farm animals possessing the stomach type illustrated
- Gumboro
- New castle
- Fowl pox
- Infectious bronchitis
- Marek’s
- Avian influenza
- Chicken anaemia virus infection
- Big liver and spleen disease
- Leukosis