62 questions. Try each one, then open the answer to check yourself and read the explanation.
Use the map of GOGO DISTRICT to answer the question. The compass direction of Ayiran from Gbadasi is
Answer: C (south-west)
Ayiran is in the lower left of the map and Gbadasi on the right, so Ayiran lies to the south-west.
Use the map of GOGO DISTRICT to answer the question. The feature marked Y on the map is
Answer: A (an oxbow lake)
Y is a horseshoe-shaped body of water beside the river's flood plain, cut off from the river: an ox-bow lake.
Use the map of GOGO DISTRICT to answer the question. The pattern of communication lines in the map is most influenced by
Answer: C (relief and drainage)
The road and railway follow the valleys between the hills and cross the river at the bridging point by Gogo.
Use the map of GOGO DISTRICT to answer the question. The main economic activity of the people around Gogo is most likely to be
Answer: A (mining)
A tin deposit is shown close to Gogo, and the railway helps carry the ore away.
Use the map of GOGO DISTRICT to answer the question. A traveller going to Gogo from the south by road is most likely to pass through a
Answer: C (bridge)
The road from the south crosses the river just south of Gogo, so it uses a bridge.
The equatorial diameter of the earth is approximately
Answer: D (12.760km)
The earth's equatorial diameter is about 12,756 km (printed with a full stop for the thousands comma).
When the sun is directly overhead at the tropic of Capricorn (23½°S) on 22nd December, the Northern Hemisphere experiences its
Answer: B (winter solstice)
With the sun overhead in the south, the north has its shortest day: the winter solstice.
If the local time at a place X is 12.00 noon when the G.M.T is 5.00a.m then X is located on longitude
Answer: A (105°E)
X is 7 hours ahead of GMT: 7 × 15° = 105°, and ahead means east.
They are formed in layers and derived from old rocks and the remains of dead organic materials. This description refers to
Answer: E (sedimentary rocks)
Layered rocks made from fragments of older rocks and organic remains are sedimentary.
Which of the following rock types is coal associated with?
Answer: C (Organically-formed sedimentary rocks)
Coal forms from compressed plant remains, an organic sedimentary rock.
A large expanse of low, level land, formed due to an uplift of part of the sea floor bordering a continent is called
Answer: E (a coastal plain)
A raised strip of former sea floor along a coast forms a coastal plain.
Mountains formed as a result of compressional forces in the earth's crust are:
Answer: B (fold mountains)
Compression squeezes rock layers into folds, producing fold mountains.
All the following are causes of mechanical weathering except
Answer: B (rain action)
Rain action is a form of erosion/chemical attack; the others break rock physically in place.
Which of the following best explains why wind action is more predominant in Arid regions than in Humid regions?
Answer: A (Loose surface materials and the absence of vegetation cover)
Dry, loose particles with no plant cover are easily moved by wind.
Use the climatic chart below to answer the question.
Month: J F M A M J J A S O N D
Temp (°C): 13 13 14 16 18 21 23 24 22 19 16 13
Rainfall (mm): 125 100 125 75 50 12 0 0 25 75 150 150
The annual range of temperature for the station is
Answer: E (11°C)
Highest 24°C (August) − lowest 13°C = 11°C.
Use the climatic chart below to answer the question.
Month: J F M A M J J A S O N D
Temp (°C): 13 13 14 16 18 21 23 24 22 19 16 13
Rainfall (mm): 125 100 125 75 50 12 0 0 25 75 150 150
The mean monthly temperature is
Answer: C (17.67°C)
The twelve temperatures add to 212°C; 212 ÷ 12 ≈ 17.67°C.
Use the climatic chart below to answer the question.
Month: J F M A M J J A S O N D
Temp (°C): 13 13 14 16 18 21 23 24 22 19 16 13
Rainfall (mm): 125 100 125 75 50 12 0 0 25 75 150 150
The annual rainfall in millimeters is
Answer: D (887)
125+100+125+75+50+12+0+0+25+75+150+150 = 887 mm.
Temperatures of adjacent coastlands are reduced when on-shore winds blow over cold currents because the
Answer: C (current influences the temperature of the prevailing winds)
Winds are chilled as they cross the cold water and carry the coolness on shore.
Winds whose direction is reversed from one season to the other are called the
Answer: D (Monsoon)
Monsoon winds blow from opposite directions in summer and winter.
Koppen's classification of climate is based on
Answer: D (precipitation and temperature)
Koppen used mean temperature and precipitation values.
The size of the individual grains of soil is referred to as the
Answer: E (texture)
Soil texture describes the proportion and size of sand, silt and clay particles.
Which of the following soil types is the most permeable?
Answer: C (Sand)
Sand has large pore spaces, so water drains through quickly.
Trees in Sudan savanna adapt to the climate of their environment by
Answer: C (shedding leaves in the dry seasons and having long tap roots with umbrella-shaped crowns)
Leaf shedding cuts water loss and long roots reach deep water during the long dry season.
Which of the following names refers to temperate grasslands?
Answer: D (Steppes)
The Steppes of Eurasia are temperate grasslands; Llanos and Campos are tropical.
In which of the following natural vegetation belts are greenheart, mahogany and ebony commonly found?
Answer: A (Selvas)
These hardwoods grow in the equatorial rain forest, called the Selvas in the Amazon.
Desert encroachment can best be controlled by
Answer: E (afforestation)
Planting trees and shelter belts holds the soil and breaks the wind.
A state of inter-dependence within the ecosystem is best achieved where the components
Answer: B (are undisturbed)
An undisturbed ecosystem keeps its natural balance of interactions.
An aquifer is
Answer: A (a permeable rock layer in which water is stored)
An aquifer is permeable rock that holds and lets water flow through it.
The best example of a non-renewable resource among the following is
Answer: C (minerals)
Minerals cannot be replaced once mined.
Which of the following factors least affects population concentration in the North-east of USA?
Answer: E (Flood)
Minerals, jobs, access and a good climate attract people; floods are not a major factor there.
Which of the following has the highest population concentration?
Answer: A (Tropical Asia)
Monsoon Asia (India, Bangladesh, Java) has the densest populations.
Which of the following is an effect of rural-urban migration on the source region?
Answer: A (Rural depopulation)
The villages people leave lose population.
One characteristic that distinguishes urban settlements from rural settlements is that
Answer: E (urban settlements are areas of secondary and tertiary activities)
Towns are centres of manufacturing (secondary) and services (tertiary).
A conurbation is a settlement
Answer: C (in which two or more towns have joined together with each retaining its identity)
In a conurbation towns merge but keep their own names.
Urbanisation can be described as the
Answer: A (growth of towns, especially in terms of human population and physical size)
Urbanisation is the growth of towns in population and area.
One relative advantage of water transport over road transport is its
Answer: C (suitability for bulky and heavy cargo)
Ships and barges carry heavy, bulky goods cheaply.
The development of hydro-electric power in Nigeria is least affected by the
Answer: D (presence of high mountains)
Nigeria's HEP stations (Kainji, Jebba, Shiroro) are on large rivers in lowland valleys; high mountains are not needed.
Which of the following best explains the drift of population from rural areas to the cities in Nigeria?
Answer: B (There are more job opportunities in the cities)
People move to towns mainly in search of jobs.
Which of the following best accounts for the decline in the importance of rail transport in Africa?
Answer: C (High competition from road transport)
Flexible road transport has taken much of the railways' traffic.
All the following are members of the ECOWAS except
Answer: D (Cameroun)
Cameroun is in Central Africa and is not an ECOWAS member.
Which of the following dams in Africa provides both irrigation water and hydro-electricity?
Answer: D (Aswan)
The Aswan High Dam stores water for irrigation and generates HEP.
(a) Explain the term migration and describe any three forms it may take
(b) State any four factors that may be responsible for migration
(c) Outline any three advantages and three disadvantages of any one type of migration mentioned in (a) above.
(a) Migration: the movement of people from one place to another to live, permanently or for a period. Forms: rural-urban; urban-rural; rural-rural; urban-urban; internal and international; seasonal; permanent; forced (refugees)
(b) Search for jobs and higher income; education and social amenities; wars, insecurity and persecution; natural disasters (drought, floods); land shortage and poor soils; marriage and family ties; government policies (resettlement)
(c) Rural-urban migration – advantages: labour for urban industries; remittances to villages; less pressure on rural land; spread of ideas and skills. Disadvantages: rural depopulation and fall in farm output; urban congestion, slums and unemployment; crime; pressure on urban amenities
Keep (c) to one type of migration.
(a) Explain four factors that may affect the growth of settlements
(b) Describe any four effects of an increase in the population size of settlements.
(a) Site and water supply; fertile land and resources (minerals); accessibility/route centres (nodal points, ports, bridging points); functions such as administration, commerce, industry and education; security/defence; government policy and investment; social amenities attracting migrants
(b) Expansion of the built-up area and suburbs; more demand for housing – slums and high rents; pressure on water, power, schools and hospitals; traffic congestion; unemployment and crime; pollution and waste; growth of markets and industries; more services and political importance
Give both positive and negative effects in (b).
Highlight the relative contributions of roads and railways to national development in any country of your choice
Nigeria (or any named country):
Roads: carry most passengers and freight; door-to-door service and flexibility; reach rural farm areas, opening them up; feed railways and ports; promote national integration (trunk roads Lagos-Kano, East-West road); create jobs (drivers, mechanics, transporters)
Railways: cheap carriage of bulky goods over long distances (groundnuts, cotton, cattle, coal, cement); linked producing areas to ports (Lagos-Kano, Port Harcourt-Maiduguri); helped growth of towns along the lines (Kaduna, Kafanchan, Zaria); safer and less congested
Overall: roads now contribute more because of flexibility, while railways remain important for heavy freight
Compare the two modes directly.
(a) Explain the term manufacturing industry
(b) Highlight the characteristic features of manufacturing industries in Tropical African countries
(c) Give any four reasons why countries embark on industrialization
(a) Secondary activity that changes raw materials or semi-finished goods into finished products of higher value using machines and labour, e.g. textiles, cement, vehicle assembly
(b) Mostly light, consumer-goods and import-substitution industries (food, drinks, textiles, soap); processing of local raw materials (cocoa, palm oil); concentrated in a few large cities and ports; much foreign ownership and capital; dependence on imported machinery, spare parts and raw materials; small scale with low output; work below capacity because of power failures; government participation
(c) Create jobs; add value to raw materials; save and earn foreign exchange; diversify the economy; raise standard of living; acquire technology and skills; national prestige and self-reliance; develop other sectors
Describe Africa's industries as they are, not as they should be.
Compare and contrast the trade relations between Nigeria and the United Kingdom with that between Nigeria and Japan
Similarities: in both, Nigeria exports mainly primary products (crude oil, cocoa, rubber) and imports manufactured goods; trade is by sea; both are major trading partners
United Kingdom: long historical/colonial ties, common language and institutions; wider range of imports (machinery, chemicals, pharmaceuticals, food, drinks); UK buys oil, cocoa, palm kernel, rubber, timber; balance often closer; UK banks and companies long established in Nigeria; shorter sea route (South Atlantic)
Japan: newer trading partner; imports dominated by vehicles, electronics, machinery, steel products; Japan buys relatively little from Nigeria (some crude oil, cotton), so Nigeria usually has a trade deficit with Japan; longer route (Cape route); no colonial ties
Give both similarities and differences.
The table below gives the climatic data for two different stations A & B, in Nigeria. Use the data to answer the questions that follow.
Station A (altitude 360 m, latitude 13°N): Rainfall (cm) J 0.0 F 0.0 M 0.0 A 1.0 M 4.8 J 9.1 J 15.5 A 24.9 S 14.5 O 1.5 N 1.5 D 0.0; Temperature (°C) 24 28 32 33 32 29 27 26 28 31 29 26
Station B (altitude 225 m, latitude 7°N): Rainfall (cm) 1.0 2.3 8.9 13.7 15.0 18.8 16.0 8.4 17.8 15.5 4.6 1.0; Temperature (°C) 27 29 29 28 27 26 24 23 25 25 26 27
(i) Identify the climatic belt to which each station belongs (ii) Outline the main climatic characteristics of each station (iii) In what ways will the agricultural practices in the two stations differ?
(i) A – tropical continental (Sudan/savanna) climate of northern Nigeria; B – tropical hinterland/sub-equatorial (wet-and-dry with double maxima) climate of southern Nigeria
(ii) A: total rainfall about 73 cm; rain only May-October with a single peak in August; dry season of 6-7 months; temperatures 24-33°C, range 9°C, hottest in April before the rains. B: total about 123 cm; rain in every month with two peaks (June and September) and a 'little dry season' in August; short dry season (December-February); temperatures 23-29°C, range 6°C, coolest in the rainy months
(iii) A: one short growing season – annual grains and legumes (millet, sorghum, groundnut, cotton, cowpea); one harvest a year; irrigation/fadama farming in the dry season; cattle rearing important; drought risk. B: long growing season with two crops of maize a year; tree crops (cocoa, oil palm, kola) and root crops (yam, cassava); little cattle because of tsetse; more weeding and leaching problems
Add up the rainfall to compare totals.
(a) On an outline map of Nigeria locate and name (i) the source areas and the destinations of two named major items of internal trade, indicate by an arrow the direction of movement of each commodity. (ii) one important town in each area
(b) Outline four factors that have favoured the development of internal trade in Nigeria
(a) e.g. cattle from the north (Kano/Maiduguri/Sokoto) to the south (Lagos/Ibadan/Port Harcourt); kola nuts from the south-west (Ibadan/Ogbomoso/Shagamu) to the north (Kano); also onions, beans from the north southward; yams from Benue/middle belt to the south; arrows showing direction
(b) Different climates and vegetation give different products in north and south; good road and rail links; common currency and no internal tariffs; large population and demand; specialisation of regions; traditional trade routes and trading peoples; markets in big towns; national unity and peace
Arrows must point from source to destination.
(a) On a sketch map of Nigeria, locate and name (i) one area important for the mining of each of limestone, tin, crude oil and coal (ii) one major town in each area
(b) Explain the importance of any one of the minerals to the economy of Nigeria
(c) Outline any four problems facing the mining industry in Nigeria.
(a) Limestone – Ewekoro/Shagamu (Ogun), Nkalagu, Sokoto, Ashaka; tin – Jos Plateau (Jos, Bukuru); crude oil – Niger Delta (Port Harcourt, Warri); coal – Enugu (Udi), Okaba
(b) Crude oil: main source of foreign exchange (over 90% of exports) and government revenue; fuel and energy; raw material for refineries and petrochemicals (fertiliser, plastics); employment; development of towns and infrastructure
(c) Lack of capital and technology; dependence on foreign companies; poor transport; fluctuating world prices; exhaustion of deposits; environmental damage (oil spills, open pits) and community unrest; illegal mining and smuggling; shortage of skilled labour
Name a town in each mining area.
(a) Identify any five problems of development in the Niger Delta region
(b) How can the problems be solved?
(a) Swampy, waterlogged terrain and many creeks making roads and buildings costly; flooding and coastal erosion; oil spillage and gas flaring destroying farmland, fisheries and air; poor infrastructure and isolation of communities; poverty and unemployment; inadequate schools, hospitals and water; communal conflicts and militancy; water hyacinth blocking waterways
(b) Special development agencies (e.g. OMPADEC/NDDC) providing roads, bridges, power and water; land reclamation and sand-filling; enforcing anti-pollution laws and ending gas flaring; oil companies investing in host communities; job creation and skills training; developing water transport and fishing; dialogue and peace-building
Match each solution to a problem.
(a) Draw a sketch map of Nigeria to show (i) the home areas of the following people: Fulani, Ibibio, Yoruba and Urhobo (ii) one major town in each home area
(b) Select any two of these peoples and explain the effects of the physical environment on their occupation and types of house
(a) Fulani – northern Nigeria (Sokoto/Kano/Yola); Ibibio – south-east, Akwa Ibom (Uyo); Yoruba – south-west (Ibadan); Urhobo – Delta State (Warri/Ughelli)
(b) Any two, e.g.:
Fulani: savanna grassland with few tsetse flies favours cattle rearing and nomadic or semi-nomadic herding; houses are light, temporary round huts of grass and poles, easy to move; settled Fulani build round mud houses with thatched roofs suited to the hot dry climate
Yoruba: forest and derived savanna with fertile soils favour farming (cocoa, yam, kola), crafts and trading; houses of mud or blocks with thatch or iron roofs, often in large compounds and towns
Urhobo/Ibibio: wet, swampy delta and forest – fishing, palm oil production, farming; houses of mud/wood and raffia palm thatch, sometimes raised on stilts near water
Explain how climate and vegetation shape each occupation and house.
(a) Outline any five factors responsible for the low density of population in some parts of West Africa
(b) In what four ways can low population density be an advantage?
(a) Desert and semi-desert climate with low, unreliable rainfall (Sahara, Sahel); poor infertile soils; tsetse fly and other diseases (sleeping sickness, river blindness); history of slave raids and wars (middle belt of Nigeria); thick forest or swamps; rugged highlands; lack of minerals, industries and amenities; poor communications
(b) Plenty of land for farming, grazing and future projects; less pressure on resources and environment, so land can recover; easier and cheaper land acquisition for development schemes and resettlement; less congestion, pollution and crime; wildlife and game reserves can be kept
Name real sparsely populated areas.
(a) Describe any five distinguishing features of plantation agriculture in East Africa
(b) Identify five factors which have favoured the practice of plantation agriculture in East Africa
(a) Large estates; one main cash crop (tea, coffee, sisal, sugar cane, pyrethrum); large capital, often owned by companies or government; many hired workers; scientific methods – fertilisers, selected seedlings, spraying; processing on the estate (tea factories, sisal decorticators); produce mainly for export; good roads and housing on the estate
(b) Cool, wet highland climate (Kenya highlands, Usambara, Mt Kilimanjaro slopes); fertile volcanic soils; availability of land (alienated to settlers); cheap labour; capital and skills from Europeans and companies; railways to ports (Mombasa, Dar es Salaam, Tanga); world demand for the crops; government support
Distinguish plantations from peasant farms.
(a) On an outline map of Africa, locate and name (i) two land-locked countries (ii) two ports, each in a different country, serving these land-locked countries (iii) the countries in which these ports are located
(b) What four major problems are facing land-locked countries in Africa?
(a) e.g. Zambia served by Dar es Salaam (Tanzania); Uganda served by Mombasa (Kenya); Mali served by Dakar (Senegal) or Abidjan; Niger served by Cotonou (Benin) or Lagos; Burkina Faso served by Abidjan (Côte d'Ivoire); Malawi served by Beira (Mozambique)
(b) High transport costs for imports and exports; dependence on neighbours' ports, roads and railways and on their goodwill; delays and congestion at foreign ports, customs formalities and transit fees; trade disrupted by border closures, wars or political disputes in transit countries; goods become dearer and exports less competitive; slower economic development
Each port must be in a different coastal country.
(a) On a map of Africa, locate and name: (i) three rivers on which hydro-electric power is generated (ii) the hydroelectric power station on each river
(b) Examine three factors that favour the generation of hydro-electric power in Africa
(c) Of what importance are hydro-electric power projects to Tropical African countries?
(a) e.g. Niger – Kainji (Nigeria); Volta – Akosombo (Ghana); Zambezi – Kariba (Zambia/Zimbabwe) or Cabora Bassa (Mozambique); Nile – Aswan (Egypt) or Owen Falls (Uganda); Zaire – Inga
(b) Many large rivers with big volume; rivers falling over plateau edges with waterfalls and rapids; deep narrow gorges for dam sites; heavy rainfall in the catchments; shortage of coal and need for cheap power; large lakes possible on impermeable rock; growing demand from towns and industries
(c) Cheap power for industries (Valco smelter, copper refining) and homes; reduces use of firewood; irrigation and water supply from the reservoirs; fishing on the lakes; lake transport; flood control; export of electricity; tourism and employment
Name the station on each river correctly.
(a) Outline any four objectives of the ECOWAS
(b) State any five problems that have limited the achievement of these objectives
(c) Suggest any three ways of solving these problems.
(a) Promote economic co-operation and integration; remove customs duties and trade barriers among members; free movement of persons, goods, services and capital; common external tariff; joint development of transport, communications, energy, agriculture and industry; harmonise economic policies and eventually a common currency; raise living standards
(b) Different currencies and monetary zones; language differences (English, French, Portuguese); members produce similar primary goods; poor transport and communication links; political instability, coups and civil wars; failure to pay dues; loyalty to former colonial powers and other groupings (e.g. CEAO); fear of domination by bigger members (Nigeria); smuggling and border closures
(c) Single currency and payment clearing house; better roads, railways and telecommunications; diversifying production to increase trade; political stability and democracy; enforcing payment of dues; harmonising laws and teaching each other's languages
Match each solution to a problem in (b).
(a) Highlight any three effects of either rotation or revolution of the earth
(b) Give reasons why: (i) all areas north of the Arctic Circle have twenty four hours of daylight on June 21 (ii) areas within the tropics have more sunshine than areas outside the tropics
(a) Rotation: day and night; deflection of winds and ocean currents (Ferrel's law/Coriolis); time difference of 4 minutes per degree of longitude; rising and falling of tides; sunrise in the east and sunset in the west. (Revolution: seasons, varying length of day and night, changing altitude of the midday sun)
(b)(i) The earth's axis is tilted 23½° and on 21 June the North Pole is tilted towards the sun; the sun is overhead at the Tropic of Cancer and its rays reach 23½° beyond the North Pole, so the whole area north of 66½°N stays in sunlight throughout the earth's rotation
(ii) The midday sun is always high and is overhead twice a year within the tropics, so rays are concentrated; day length is about 12 hours all year with no long winter nights; rays pass through less atmosphere
Use the tilt of the axis in (b).
(a) Using appropriate diagrams, explain the process of formation of a (i) river capture (ii) waterfall
(b) Describe one way in which each of the two features above is useful to man
(a)(i) River capture (diagrams before and after): a vigorous river with a steeper gradient or on softer rock cuts back by headward erosion through the watershed; it reaches and diverts the headwaters of a weaker neighbouring river; features: elbow of capture, wind gap, misfit stream (beheaded river)
(ii) Waterfall (diagram): where a band of hard rock lies across a river's course over softer rock, the soft rock is eroded faster; a steep step forms over which water falls; hydraulic action and abrasion form a plunge pool and undercut the hard rock, which collapses so the fall retreats upstream leaving a gorge (also formed by faults, hanging valleys, plateau edges)
(b) River capture: increased water in the capturing river for HEP, irrigation or water supply; wind gaps give routes for roads and railways. Waterfall: hydro-electric power; tourism; marks head of navigation/site for settlement
Label elbow of capture, wind gap and misfit.
(a) State Koppen's five major climatic groups
(b) Describe the distribution and major features of the first group in Koppen's classification
(c) Give three reasons why the Koppen's system of climatic classification is the most widely accepted
(a) A – tropical rainy; B – dry; C – warm temperate (mild winter); D – cold snow-forest; E – polar
(b) Group A lies between about 23½°N and S: Amazon and Zaire basins, Guinea coast, South-East Asia, northern Australia, Central America; every month above 18°C, no winter, heavy rainfall exceeding evaporation; Af (rain all year), Am (monsoon, short dry season), Aw (savanna, dry winter)
(c) Uses simple, measurable data (mean temperature and rainfall) available for most stations; boundaries match natural vegetation; precise numerical limits so any station can be classified; flexible letter system giving many sub-types; useful at different levels of study
Group A: every month above 18°C.
Differentiate between the Equatorial and the Tropical continental climates under the following (a) location (b) temperature characteristics (c) rainfall distribution
(a) Equatorial: about 0-10° N and S – Zaire basin, Amazon basin, Guinea coast, Malaysia/Indonesia. Tropical continental: about 10-20° N and S – Sudan belt of West Africa, East African plateaus, Brazilian highlands (campos), llanos, northern Australia
(b) Equatorial: high and uniform, mean about 27°C, annual range only 2-3°C; high humidity. Tropical continental: high, mean about 21-27°C, annual range larger (5-10°C), hottest just before the rains; cooler harmattan nights; large diurnal range
(c) Equatorial: rain all year, about 1,500-2,500 mm, double maxima after the equinoxes, convectional afternoon storms, no dry month. Tropical continental: seasonal summer rain, about 750-1,500 mm, single maximum, long dry season (4-7 months), rainfall decreasing poleward
Write each heading as a direct contrast.
(a) Distinguish between an ecosystem and a food chain
(b) Explain the interdependence of the biotic and abiotic components of the environment
(a) Ecosystem: a community of living organisms interacting with each other and with their non-living environment in a given area (e.g. a pond, a forest). Food chain: the sequence of feeding relationships through which energy passes from producers to consumers, e.g. grass → grasshopper → toad → hawk; it is only one part of an ecosystem
(b) Plants (biotic) need sunlight, water, carbon dioxide and soil nutrients (abiotic) for photosynthesis and growth; animals need oxygen, water and shelter; plants release oxygen and use CO₂, animals release CO₂ in respiration; decomposers return nutrients to the soil; vegetation protects soil from erosion and adds humus; climate controls which organisms live in an area while plants modify the micro-climate
Show the exchange going both ways in (b).
Write explanatory notes on each of the following (a) deforestation (b) drought (c) pollution
(a) Deforestation: removal of forest cover for farming, lumbering, fuel, mining, roads and settlements without replanting; effects – soil erosion, loss of timber and wildlife, flooding, climate change, desertification; control – afforestation, forest reserves, controlled felling, forest guards
(b) Drought: a long period of very low or no rainfall with high temperatures; causes crop failure, death of livestock, famine, water shortage, migration and desert encroachment; control – irrigation, dams and wells, drought-resistant crops, mulching, shelter belts
(c) Pollution: release of harmful substances into air, water or land (gas flaring, vehicle exhaust, sewage, industrial effluent, oil spills, refuse, noise); effects – diseases, death of fish and crops, acid rain, poor visibility; control – laws and fines, waste treatment, proper disposal, public education
Define, give causes/effects and control for each.