Correct Answer: C. 4 - 5

Explanation

(a) Role of soil organisms in the formation of soils are.-

(i) The microbes by their enzymes, break down rock particles.

(ii) Burrowing activities of microbes enhance aeration and introduction of water into the rocks, thereby enhancing rock break down. ( Earthworm activities).

(iii) and other rodents cause pressure by their burrowing activities, thereby creating channels and tracks through which air and water penetrate to promote the breakdown of rocks.

(iv) Activities of earthworm, ants, termites and crickets disintegrate rocks through engulfing, crushing, and expulsion of smaller soil particles.

(v) Soil micro -organism incorporate organic matter into the soil due to their burrowing activities, thus enhancing the faster disintegration of rocks.

(vi) The wastes of organic acidic and hasten the disintegration of rocks.

(vii) Fungi and soil - borne algae act on soil organic matter which releases acids that promote rock disintegration.

(viii) Lower plant forms, such as lichens and mosses can disintegrate rock by their activity through the release of corrossive substances from their fast holds.

(ix) As plant roots without organisms into the soil, they encounter and breakdown rocks as they force their way through rocks.

(x) Dead organism accumulate and aid soil formation

(b) Ways in which soil organisms improve soil for growth of crops are:

(i) Improve soil structure and granulation.

(ii) Improve soil aeraton.

(iii) Improve soil water percolation or drainage.

(iv) Increase organic matter content of soil.

(v) Increase soil colloidal properties

(vi) Enhance the cation exchange capacity of the soil.

(vii) Through burrowing, they eave holes for crop root to penetrate.

(viii) Increase the mineral or nutrient status of the soil

(ix) Stabilize soil pH through the increase of soil organic matter

Correct Answer: D. The price increases

Explanation

In economics, when demand exceeds supply, it creates a shortage. The price of the product will increase until the quantity demanded is equal to the quantity supplied, a state known as equilibrium. This is because the high demand and low supply create a competitive market where buyers are willing to pay more to secure the product.

Correct Answer: D. thermostat

Explanation

(a) Factors of production include: (i) land (ii) labour (iii) capital and (iv) entrepreneurship.

(i) Land includes all the gift of nature e.g. water, soil, air etc. It is used in production. Land is scarce .or limited in supply. It is immobile and heterogeneous and subject to the law of diminishing returns. The reward of land is rent. Land can appreciate or depreciate. Its suitability influences output and its location determines its value. Land can be used as collateral for bank loans.

(ii) Labour refers to all human effort put into production. Sources of labour include personal labour, community labour, family labour, hired. labour etc. could be skilled or unskilled. Its reward is salary or wages. Labour is regarded as a variable factor of production. Its output can be improved by training. It is mobile.

(iii) Capital refers to all man-made productive.assets which are used in production e.g. farm buildings, tools, money etc. It is mobile e.g. tractor. The amount determines volume or scope of operation. Its reward is interest. It can be circulatory or variable e.g. money seed, chick etc. Capital can be fixed e.g. building, machines etc. It can be obtained in form of loan or subsidies and can appreciate or depreciate

(iv) Entrepreneurship: refers to the person who cordinates, organises and controls other factors of production. He bears the risk. He implements decision. Entrepreneurship involves the use of mental energy in production. He minimizes cost of production and maximizes profit. His quality influences the output.

(b) (i) A farm manager plans all the farm operations (ii) He makes short and long term decision. (iii) He organises the farm enterprise and directs the smooth running of the farm. (iv) He also supervises all work done and sets up a mechanism that will enable him to determine the progress of the farm. (v) A farm manager coordinates and control various activities in the various farm units.

Correct Answer: C. high population growth rate

Correct Answer: B. suckers

Correct Answer: D. overgrazing

Explanation

(a) Ways in which science and technology have contributed to agricultural development:

(i) Crop protection

- Producing equipment for pesticides and herbicides application

- Herbicides for weed control

- Nematicides for the control of nematodes

- Fungicides for the control of fungi

- Pesticides for the control of pests in plants

- Insecticides for control of insects

-Rodenticides for control of rodents

- Avicides for control of birds

- Molluscides for the control of molluscs

- Bactericides for the control of bacteria

- Sterilization of plant materials

- Soil sterilization

- Breeding disease resistant varieties of crops

- Irradiation to enhance storage of farm produce.

(ii) Climatology and meteorology:

- Forecasting rainfall pattern to determine planting and harvesting dates

- Forecasting temperatures to produce drying and prediction of disease and pest outbreak

- Monitoring of wind speed

- Monitoring of wind direction

- Cloud seeding for rainfall

- Determination of relative humidity

- Monitoring cloud formation and movement

- Measurement of solar radiation

- To determine types of crops to plant e.g. early maturing

- Producing equipment for weather forcasting

(b) Functions of farm machines and implements

(i) Bulldozer:

- Leveling of land surface

- Moving large quantities of earth

- Uprooting stumps

- Removing, obstacles

- Felling trees Clearing virgin lands/Bush clearing

- Road construction on farms in rural areas

(ii) Combine harvester: Harvesting of cereals

- Threshing of cereals

- Winnowing of harvested grains

- Bagging of harvested grains

(iii) Tractor

-Transportation of human beings

-Pumping of water through the use of Power-Take-Off (P. T. 0)

-Lifting of equipment with the aid of the hydraulic system e.g. mower

-Allows the use of farm implements for land preparation e.g. plough, harrow, ridger etc.

-Provides power to drive stationary farm equipment e.g. milking machines, shellers, etc.

-Generates electricity

- For carting farm produce and inputs /haulage

(iv) Sprayer

- Application of herbicides, fungicides, insecticides, etc.

- Application of liquid fertilizers

-Application of plant hormones

(v) Planter

- Sowing of seeds

- Application of fertilizers

- Application of nematicides/ pesticides

Correct Answer: A. lose viability at a fast rate