WAEC SSCE - Agricultural Science - 2016 (Practical)
Question 1 Rapport
The diagram above illustrates an experimental setup to determine a soil property.
Study them carefully and answer the question that follows;
(a) Suggest a suitable title for the experiment. [1 mark]
(b) Outline the procedure for carrying out the experiment.[ 7 marks]
(c) identify the soil samples in diagrams 1, Il, and ll
(d) State two precautions to be taken when carrying out the experiment.[ 2 marks )
(e)(i) Which of the soil samples is prone to waterlogging?
(ii) Give one reason four your answer in (e)(i)
The diagram shows three identical setups labelled I, II and III. In each, a funnel holds a soil sample, with a plug of cotton wool at the neck of the funnel. Each funnel is mounted over a measuring cylinder which collects the water that passes through the soil. The three funnels hold soils of different texture, and the amount of water collected in each cylinder differs.
(a) Suitable title (1 mark)
An experiment to determine the rate of water percolation (drainage/permeability) through different soil types.
(b) Procedure (7 marks)
- Set up three funnels of equal size and place a plug of cotton wool of equal thickness in the neck of each, to hold back the soil while letting water pass.
- Weigh out equal masses of three different soil samples (sample I, II and III) and place one sample in each funnel.
- Mount each funnel on a clean, dry measuring cylinder so that water dripping through is collected.
- Measure out an equal volume of water (for example \(100\ \text{cm}^3\)) for each setup using a measuring cylinder.
- Pour the water gently onto the surface of each soil sample at the same time and start a stopwatch.
- Allow the water to percolate for the same fixed time (for example 5 minutes), then read the volume of water collected in each cylinder.
- Record the volumes for I, II and III and compare them. The soil that allows the largest volume through in the given time has the highest permeability; the soil that allows the least has the poorest drainage.
(c) Identity of the soil samples
- Diagram I - Clayey soil (fine, closely packed particles).
- Diagram II - Loamy soil (mixture of medium sized particles).
- Diagram III - Sandy soil (coarse, loosely packed particles).
(d) Two precautions (2 marks)
- Use equal masses of soil, equal volumes of water and cotton wool plugs of equal thickness in all three setups, so the comparison is fair.
- Pour the water onto all three samples gently and at the same time, and read the collected volume at exactly the same time interval to avoid errors.
(e)(i) The soil most prone to waterlogging is sample I (clayey soil).
(e)(ii) Clayey soil has very fine particles and small pore spaces (low porosity and low permeability), so water drains through it very slowly and collects on and within the soil, leading to waterlogging. This is confirmed in the experiment by the small volume of water passing into cylinder I compared with the larger volumes collected under the loamy (II) and sandy (III) samples.
Détails de la réponse
The diagram shows three identical setups labelled I, II and III. In each, a funnel holds a soil sample, with a plug of cotton wool at the neck of the funnel. Each funnel is mounted over a measuring cylinder which collects the water that passes through the soil. The three funnels hold soils of different texture, and the amount of water collected in each cylinder differs.
(a) Suitable title (1 mark)
An experiment to determine the rate of water percolation (drainage/permeability) through different soil types.
(b) Procedure (7 marks)
- Set up three funnels of equal size and place a plug of cotton wool of equal thickness in the neck of each, to hold back the soil while letting water pass.
- Weigh out equal masses of three different soil samples (sample I, II and III) and place one sample in each funnel.
- Mount each funnel on a clean, dry measuring cylinder so that water dripping through is collected.
- Measure out an equal volume of water (for example \(100\ \text{cm}^3\)) for each setup using a measuring cylinder.
- Pour the water gently onto the surface of each soil sample at the same time and start a stopwatch.
- Allow the water to percolate for the same fixed time (for example 5 minutes), then read the volume of water collected in each cylinder.
- Record the volumes for I, II and III and compare them. The soil that allows the largest volume through in the given time has the highest permeability; the soil that allows the least has the poorest drainage.
(c) Identity of the soil samples
- Diagram I - Clayey soil (fine, closely packed particles).
- Diagram II - Loamy soil (mixture of medium sized particles).
- Diagram III - Sandy soil (coarse, loosely packed particles).
(d) Two precautions (2 marks)
- Use equal masses of soil, equal volumes of water and cotton wool plugs of equal thickness in all three setups, so the comparison is fair.
- Pour the water onto all three samples gently and at the same time, and read the collected volume at exactly the same time interval to avoid errors.
(e)(i) The soil most prone to waterlogging is sample I (clayey soil).
(e)(ii) Clayey soil has very fine particles and small pore spaces (low porosity and low permeability), so water drains through it very slowly and collects on and within the soil, leading to waterlogging. This is confirmed in the experiment by the small volume of water passing into cylinder I compared with the larger volumes collected under the loamy (II) and sandy (III) samples.
Question 2 Rapport
Study specimens G (GRASSHOPPER), H (BEAN BEETLE), I (BIRD), and J (RAT) carefully and answer the following questions.
(a)(i) Classify specimens G and H according to their feeding habits.
(ii) Name one part of crops damaged by each of specimens G and H.
(ii) State three ways in which specimen H is economically important. (3 marks ]
(b) State four ways of controlling each of specimens I and J
(a)(i) Classification of G and H by feeding habit
- Specimen G (grasshopper): a biting and chewing insect pest.
- Specimen H (bean beetle): a biting and chewing insect pest (its larva and adult chew/bore into the seed).
(a)(ii) Part of crop damaged by each
- Grasshopper (G): damages the leaves of the crop.
- Bean beetle (H): damages the seeds/grains (cotyledons of stored beans).
(a)(iii) Three ways specimen H (bean beetle) is economically important
- It bores into and eats stored bean seeds, reducing the weight and quantity available.
- It lowers the market value and quality of the beans, causing financial loss.
- It destroys the germinating power (viability) of seeds meant for planting, and its holes allow entry of moulds that spoil the produce.
(b) Four ways of controlling specimens I and J
| Specimen | Four control measures |
|---|---|
| I (bird) | Use scarecrows and bird scarers; net or cage nursery/seed beds; shoot or trap destructive birds; grow early, uniform-maturing and resistant varieties and harvest promptly |
| J (rat) | Set rat traps; use rat poisons (rodenticides/baits); keep the farm and store clean by clearing bushes and hiding places; keep natural enemies such as cats and maintain rat-proof storage structures |
Détails de la réponse
(a)(i) Classification of G and H by feeding habit
- Specimen G (grasshopper): a biting and chewing insect pest.
- Specimen H (bean beetle): a biting and chewing insect pest (its larva and adult chew/bore into the seed).
(a)(ii) Part of crop damaged by each
- Grasshopper (G): damages the leaves of the crop.
- Bean beetle (H): damages the seeds/grains (cotyledons of stored beans).
(a)(iii) Three ways specimen H (bean beetle) is economically important
- It bores into and eats stored bean seeds, reducing the weight and quantity available.
- It lowers the market value and quality of the beans, causing financial loss.
- It destroys the germinating power (viability) of seeds meant for planting, and its holes allow entry of moulds that spoil the produce.
(b) Four ways of controlling specimens I and J
| Specimen | Four control measures |
|---|---|
| I (bird) | Use scarecrows and bird scarers; net or cage nursery/seed beds; shoot or trap destructive birds; grow early, uniform-maturing and resistant varieties and harvest promptly |
| J (rat) | Set rat traps; use rat poisons (rodenticides/baits); keep the farm and store clean by clearing bushes and hiding places; keep natural enemies such as cats and maintain rat-proof storage structures |
Question 3 Rapport
Study specimens A (RANGING POLE), B (SURVEY PIN) and C (MEASURING TAPE) carefully and answer the following question.
(a) Describe specimen A. (3 mark)
(b) State two uses each of the specimens A, B and C.
(c) State two ways of maintaining each of specimens A, B, and C
(a) Description of specimen A (ranging pole)
A ranging pole is a straight, round metal or wooden pole about 2 to 3 metres long, pointed with a metal shoe at the lower end so that it can be driven into the ground, and painted in alternating bands of red and white (or black and white) at intervals of 0.5 metre so that it can be seen clearly from a distance.
(b) Two uses of each specimen
| Specimen | Two uses |
|---|---|
| A (ranging pole) | Used for ranging or setting out straight lines during survey; used for marking points/stations on the field |
| B (survey pin / arrow) | Used for marking the ends of each tape length during chaining; used for counting the number of chain/tape lengths measured |
| C (measuring tape) | Used for measuring distances and lengths on the field; used for measuring the dimensions of plots for area calculation |
(c) Two ways of maintaining each specimen
| Specimen | Two ways of maintenance |
|---|---|
| A (ranging pole) | Clean and dry after use and store upright; repaint the coloured bands and oil the metal shoe to prevent rust |
| B (survey pin) | Clean, dry and oil/grease to prevent rust; keep on a ring and store in a dry place, straightening any bent pin |
| C (measuring tape) | Wipe clean and dry, then wind back into its case after use; oil metal tapes to prevent rust and avoid kinking or overstretching |
Détails de la réponse
(a) Description of specimen A (ranging pole)
A ranging pole is a straight, round metal or wooden pole about 2 to 3 metres long, pointed with a metal shoe at the lower end so that it can be driven into the ground, and painted in alternating bands of red and white (or black and white) at intervals of 0.5 metre so that it can be seen clearly from a distance.
(b) Two uses of each specimen
| Specimen | Two uses |
|---|---|
| A (ranging pole) | Used for ranging or setting out straight lines during survey; used for marking points/stations on the field |
| B (survey pin / arrow) | Used for marking the ends of each tape length during chaining; used for counting the number of chain/tape lengths measured |
| C (measuring tape) | Used for measuring distances and lengths on the field; used for measuring the dimensions of plots for area calculation |
(c) Two ways of maintaining each specimen
| Specimen | Two ways of maintenance |
|---|---|
| A (ranging pole) | Clean and dry after use and store upright; repaint the coloured bands and oil the metal shoe to prevent rust |
| B (survey pin) | Clean, dry and oil/grease to prevent rust; keep on a ring and store in a dry place, straightening any bent pin |
| C (measuring tape) | Wipe clean and dry, then wind back into its case after use; oil metal tapes to prevent rust and avoid kinking or overstretching |
Question 4 Rapport
Study specimens N (BONE), 0 (EGG), P (ROUNDWORM) and Q (TICK) carefully and answer the following questions.
(a) Name three industries that use each of specimens N and O
(b) State five effects of specimen P on the host. (5 marks ]
(c) State four ways of controlling specimen Q on the farm. [4 marks)
(a) Three industries that use specimens N (bone) and O (egg)
| Specimen | Three industries |
|---|---|
| N (bone) | Animal feed industry (bone meal); fertiliser industry (bone/phosphate meal); gum, glue and gelatine industry (and soap/button making) |
| O (egg) | Food and confectionery/bakery industry; pharmaceutical/vaccine industry (eggs used to culture vaccines); cosmetics industry (and poultry/hatchery industry) |
(b) Five effects of specimen P (roundworm) on the host
- It feeds on digested food in the gut, causing loss of nutrients, emaciation and loss of weight.
- It causes anaemia and general weakness of the animal.
- Heavy infestation blocks the intestine and may cause pot belly and digestive disturbance.
- It lowers productivity, that is reduced growth, milk, meat or egg output.
- It damages the intestinal wall and internal organs and may cause death in severe cases.
(c) Four ways of controlling specimen Q (tick) on the farm
- Dip or spray animals regularly with acaricides (tick chemicals).
- Hand-pick and destroy ticks from infested animals.
- Practise rotational grazing and clear/burn overgrown pastures to destroy the tick habitat.
- Quarantine and treat newly bought or infested animals before mixing them with the herd, and drain marshy areas.
Détails de la réponse
(a) Three industries that use specimens N (bone) and O (egg)
| Specimen | Three industries |
|---|---|
| N (bone) | Animal feed industry (bone meal); fertiliser industry (bone/phosphate meal); gum, glue and gelatine industry (and soap/button making) |
| O (egg) | Food and confectionery/bakery industry; pharmaceutical/vaccine industry (eggs used to culture vaccines); cosmetics industry (and poultry/hatchery industry) |
(b) Five effects of specimen P (roundworm) on the host
- It feeds on digested food in the gut, causing loss of nutrients, emaciation and loss of weight.
- It causes anaemia and general weakness of the animal.
- Heavy infestation blocks the intestine and may cause pot belly and digestive disturbance.
- It lowers productivity, that is reduced growth, milk, meat or egg output.
- It damages the intestinal wall and internal organs and may cause death in severe cases.
(c) Four ways of controlling specimen Q (tick) on the farm
- Dip or spray animals regularly with acaricides (tick chemicals).
- Hand-pick and destroy ticks from infested animals.
- Practise rotational grazing and clear/burn overgrown pastures to destroy the tick habitat.
- Quarantine and treat newly bought or infested animals before mixing them with the herd, and drain marshy areas.
