Correct Answer: C. photosynthesis

Correct Answer: C. recessiveness

Explanation

(a) Discussion of the cultivation of cassava:

(i) Soil requirements:

-A well-drained/sandy/friable loamy soil.

- soil rich in organic matter.

(ii) Spacing: 1m x 1m. (iii) Disease:

- Cassava mosaic

- Leaf spot

- Bacterial leaf blight

- Tuber rot/white thread

-Anthracuose.

(iv) Pest:

- Green spider mites

- Grasshoppers

- Mealy bugs

- Rodents

- White flies

- Monkeys.

(b) Difference between natural and artificial pasture: Natural pasture refers to an area of land covered with forage grasses and legumes which are not planted by man. While/on the other hand/but/whereas. Artificial pasture refers to an area of land covered with forage grasses and legumes which are deliberately planted by man.

(c) Explanation of the term disease in crop production: Disease refers to a deviation from the normal health status/ condition of a crop presenting marked symptoms.

(d) Mendel 's law of independent assortment of genes: Mendel 's law of independent assortment of genes states that each character behaves as a separate unit and is inherited independently of any other character. OR This law states that when two pure/true-bred organisms with two or more pairs of contrasting characters are crossed, the characters assort independently in the second filial generation.

(e) Explanation of regeneration as a forest management practice: - Regeneration is the process of forest regrowth after it has been exploited which can be natural or artificial.

(f) Effects of deforestation:

- Loss of soil nutrients.

- Permanent destruction of indigenous forests.

- Soil erosion.

- Desert encroachment desertification.

- Loss of bodiversity/imbalance in the ecosystem.

-Disruption of hydrological cycle.

- Increase in atmospheric carbon(iv) oxide concentration.

-Destruction of micro climate/increased environmental temperature.

- Loss of soil organic matter.

- Reduction in soil microbial activities.

-Exposure of the soil to direct rays of the sun.

Explanation

(a) Advantages and disadvantages of biogas as asource of farm power

Advantages

- It reduces environmental pollution

- It is easily controlled/easy to operate

- Animal dung is cheap

- Provides economic value to animal wastes/provides proper use of animal wastes

- It can be used for different farm operations like heating the brooder house, drying etc

Disadvantages

• It requires high technical know-how
• It is not a common source of farm power
• Its use is limited to areas where there is abundance of animals
• it is expensive to set up and maintain

(b) Simple farm tool

Some tools used in the farm are:

1. Cutlass

2. Hoe

3. Garden fork

4. Hand fork

5. Trowel

6. Rake

7. Shears

8. Secateurs

9. Sprayers

10. Watering can

11. Sickle

12. Axe

13. File

14. Head pan

15. Wheel barrow

16. Spade

17. Shovel

18. Mattock

19. Mallet

20. Tapping knife

21. Dibber

22. Budding knife

(c)Common storage structures and processing structures found on farmstead in West Africa

Storage structures

• - Barns
• - Bins
• - Cribs
• - Silos
• - Drums
• - Cages
• - Bags
• - Baskets
• - Rhumbu
• - Farm store/warehouse
• - Underground pits
• - Platforms
• - Cold room/cold store

Processing structures

• - Abattoir
• - Milk pasteurizing shed
• - Fish or meat smoking shed
• - Rice mill
• - Cassava mill
• - Oil mill(for oil crops)
• - Curing house for tobacco
• - Shelling barn

(d)Explanation ofdenitrification

This is the process whereby soil nitrates are converted to nitrogen gas, nitric oxide or nitrous oxide through the activities of denitrifying bacteria

(e) Description of soil components

(i) Mineral Matter: Form the solid parts of the soil which are derived from weathered rocks

• - Represents 45% per volume of a soil sample
• - Holds water and air for plant use
• -Source of plant nutrients
• -Provides anchorage to plants

(ii) Organic matter:

• Represents a mixture of plant and animal materials at different stages of decomposition in the soil
• Represents 5% per volume of a soil sample
• Improve soil structure/binds soil particles together
• Source of plant nutrients after decomposition

Correct Answer: C. replanting

Correct Answer: B. between conception and parturition

Correct Answer: B. an undulating land

Correct Answer: C. weaning

Explanation

(a) The Gunter's chain consists of a brass handle at each end. The chain is entirely metallic. It consists of units, each of which is a straight piece and three oral rings. The commonest length available is 30.5m.

(b) Given Base length of farm 2km =200m, Perpendicular length = 1200m, Area of farm = 1/2(base x height) = 1/2(2000m x 1200m) = (24000000m²2) = 1200000m² or 1.2km² Alternatively: Base length of farm, = 2km Perpendicular length = 1200m, = 1.2km Area of farm = 1/2 (base x height) 1/2 (2km x 1.2km) 1/2 (2.4 km2) 1.2 km²

(c) Necessary precautions to be taken in order to eliminate errors when chaining farm land are: (i) pulling of taut chains, tapes or ropes. (ii) avoidance of errors of transposing figures on papers. (iii) equipment such as theodolite should be placed on a perfect horizontal plane. (iv). all chains, tapes, ropes, etc. must be properly alligned before taking measurement (v) avoidance of error of parallax when reading measurements. (v) make sure the chain is not faulty before use.

(d) Factors to be considered when choosing a garden site for a school include: (i) topography (ii) drainage (iii) availability of good top soil (iv) adequa water supply (v) closeness to the school (vi) good access road from the school to the garden.

Correct Answer: B. 18 - 21