Question 3
(a) Draw and label the carbon cycle. (7 marks)
(b) Give three reasons why the carbon cycle is important to crops and animals. (3 marks)
(c) List four farm structures used in storing harvested crops. (4 marks)
Observation
Candidates responses in Question 3 was below average due to Questions 3(a) and (b).
- Majority of candidates who attempted this question could not draw and label the carbon cycle correctly. Many candidates either drew a diagram without any corresponding arrow or the arrows were misdirected. Furthermore, some candidates drew the water cycle.
- Many candidates were also unable to state the importance of the carbon cycle to crops and animals.
- Question 3(c) and (d) was fairly attempted by candidates although some candidates could not differentiate between ‘rhombus’, a shape in mathematics and ‘rhumbus’, a storage structure in agriculture.
The expected answer include:
- (a) Diagram of the carbon cycle
(b) Reasons why the carbon cycle is important to crops and animals
- Provision of carbon which is the building block of all organic matter
- Carbon in the form of carbon (IV) oxide (CO2) in the air is used by plants to manufacture their food through the process of photosynthesis
- The removal of carbon (IV) oxide (CO2) from the air helps to purify the air
- Both plants and animals release carbon (IV) oxide (CO2) during respiration and this helps to maintain the atmospheric level of carbon (IV) oxide (CO2)
(c) Farm structures used in storing harvested crops
- Silo - Crib
- Barn - Rhumbus
- Bin/ hermitic container - Basket
- Underground pit - Bag/sack
(d) Effects of lice in poultry production
- Anaemia - Transmit diseases
- Cause low feed intake - Cause low water intake
- Irritation and skin itching - Reduction in egg production
- Loss of feathers - Loss of weight
- Weakness - Increased cost of production
- Restlessness
- Create wounds which is a source of secondary infection