Explanation

Weathering is the breaking down of rock masses (rock minerals) into simpler forms through the agents of physical, chemical and biological processes. (a)(i) Types of weathering include: (i) Physical weathering (ii) Chemical weathering. (b) Factors which influence weathering are: 1. Climatic factors: (a) Temperature (b) Rainfall/ Water (c) Wind. 2. biological factors / Living organisms: (a) Man (b) Plant (c) Animals 3. Topography 4. Parent Materials 5. Time.

1. Climate: (a)Temperature: (i) changes in temperature bring about cracks in rocks. (ii) these differences in temperature cause aggregates onerals of which rocks are made up to expand to varying degrees since they have different coefficients or expansion. The rocks are stressed, hence peeled and cracked.

b. Rainfall/Water: (i) when water falls on rocks in form of rain, it moves or transports weathered rock and rock particles down the ground, thereby, exposing unweathered part of the rock to other agents. e.g. temperature changes for further weathering. (ii) The rock particles carried down the rok sides by rainwater are abrassive, thereby, causing mechanical breakdown of rock surfaces which carried along with it rain water down the drain. (iii) in temperate countries and other areas with temperate climate, ice is formed in cracks from water collected in such cracks. Since water increases in volume when it freezes, the ice serves as a wedge, thereby, widening the cracks, and cause promoting rock disintegration. (iv) water dissolves minerals in rocks, thereby, causing weathering. (v) involves the attachment of water molecules to the substance or chemical compound being attacked. This may lead to the weakening of the rock mineral concerned, and in turn, weaken the rock which contains that minerals: leading to its breakdown. Wind is more active in arid regions. (1). It also carnes rock particles which collides against each other, thereby causing abrassions and chipping off of particles

2. Biological factors or living organisms: (i) activities of man e.g.in road construction, mining, farming breakdown rocks physically. (ii) plants contribute immensely to weathering of rocks through their roots. (iii) roots of trees and shrubs growing by the side of rocks or on the rocks, penetrate into cracks in the rocks. These widen and break-down the rocks. (iv) plants' roots exude certain susbtances or chemicals which cause the dissolution of rock minerals. (v) burrowing animals, e.g. earthworms, rodents, e.t.c. cause weathering by their activities.

3. Topography: (i) the gradient of the land affects the velocity of the running water or ice on the rock. (ii) this affects the rates, the force ( pressure) of collision of these particles when they are moved or transported from their original position.

4. Parent Materials: (i). the type of parent material affects the rate of weathering. (ii) softness/hardness of the material affects the rate of weathering.

5. Time: (i) the longer the rocks are exposed to weathering processes, the more the rock will weather

Correct Answer: B. Aquatic animals

Correct Answer: B. aluminium

Explanation

(a)(i)Difference between intensive system and extensive system of livestock management

Intensive system of livestock management is a system in which livestock are kept under confinement at a high stocking rate with adequate provision for housing, feeding and health care

Whereas

Extensive system of livestock management is a system in which livestock are kept at low stocking rate with little or no provision for housing, feeding and health care.

(ii)Disadvantages of keeping livestock on free range system

• Exposes animals to infectious diseases.
• Exposes animals to predators.
• Difficulty in keeping records for individual animals.
• Exposes animals to pests.
• Feeding cannot be controlled.
• Breeding programme cannot be planned.
• Exposes animals to thieves.
• Animals dissipate energy in search of food and water.
• Characterized by slow growth rate and productivity.
• Exposes animals to environmental hazards and accidents.

(c) Ways in which ornamental plants are important

• Source of foreign exchange
• Source of income
• Source of employment
• Used to beautify the environment
• Used in landscaping
• Promote tourism
• Serve as wind break
• Some have medicinal value
• Used to demarcate boundaries
• Used for marking avenues
• Used for educational/research purposes
• Used for visual screening or concealing views to provide privacy
• Some ornamental plants are edible/used as food for humans/animals
• Leguminous ornamental plants fix nitrogen into the soil
• Some ornamental plants produce fragrance which give pleasure to people
• Help to reduce night blur on major roads to prevent accidents in the night
• Used in bouquets, garlands and wreaths
• The flowers of some ornamental plants are used in the preparation of dyes

Correct Answer: A. through the blood vessels located in the placenta

Correct Answer: C. building houses

Correct Answer: B. drainage

Correct Answer: D. entrepreneurship

Correct Answer: B. Engine oil

Explanation

The engine oil of a tractor requires daily checking. Therefore, choice B is correct

Correct Answer: C. veal