WAEC SSCE - Geography - 1995

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The feature that is not associated with coastal erosion is the marine dune. Coastal erosion is a natural process that occurs along the coastlines due to the impact of waves and other coastal processes. The other four features mentioned in the options are all associated with coastal erosion. A wave-cut platform is a flat, rocky surface formed by the erosion of coastal cliffs by waves. A stack is a tall, vertical column of rock that stands in the sea near a coastline. A geo is a narrow inlet or cove between steep cliffs, created by coastal erosion. A bay is a broad inlet of the sea where the land curves inward, usually with a beach or a small port. However, a marine dune is not associated with coastal erosion, as it is a feature that forms on sandy beaches and dunes due to the accumulation of sand by the action of wind.

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Soil erosion is the process by which soil is moved from one place to another by agents such as water, wind, and waves. However, the principal agents in soil erosion are water and wind. Water erosion occurs when rainfall, runoff, and floodwater move soil particles, while wind erosion occurs when wind moves soil particles, especially in arid and semi-arid regions.

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The satellite of the earth is the Moon. A satellite is an object that orbits around a larger object, and in this case, the Moon orbits around the Earth. The Moon is our closest neighbor in space, and it takes about 27.3 days to orbit around the Earth. The Moon is also the fifth-largest moon in the solar system and the largest relative to its host planet. It plays an important role in our daily lives, causing tides in the ocean and influencing our planet's rotation.

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When two separate towns grow and expand to the point where they merge together, they form a new settlement that is called a conurbation. A conurbation is a large urban area comprising several towns or cities that have grown together and become one continuous built-up area. This often happens as a result of urbanization, where people migrate from rural areas to urban centers in search of better economic opportunities and a higher standard of living. As more and more people move into these urban areas, the separate towns begin to grow and expand until they eventually merge into one large conurbation.

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An active volcano is a volcano that erupts periodically or has erupted recently. It is different from a dormant volcano, which is not currently erupting but has the potential to erupt in the future, and an extinct volcano, which has not erupted for a long time and is not expected to erupt again. Active volcanoes are constantly monitored by scientists to detect any signs of activity that could indicate an imminent eruption. Some active volcanoes erupt regularly, while others have irregular eruptions. Eruptions can vary in intensity, and some active volcanoes can be very destructive, causing damage to the surrounding area and endangering the lives of people living nearby.

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Humus in the soil helps to retain more moisture, which is important for plant growth. It acts like a sponge, holding onto water and releasing it slowly so that plants can access it over time. Humus also improves soil structure and texture, making it easier for roots to penetrate and access nutrients. It does not make the soil sparkle or very soft, nor does it make it hard.

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Soil erosion is a major problem that occurs when topsoil is washed away or blown off, leading to the loss of valuable soil nutrients, decreased soil fertility, and loss of cultivable land. The consequences of soil erosion also include increased water pollution, decreased water reservoirs, and the aggravation of drought conditions. Therefore, it is evident that soil erosion does not increase the yield per hectare; rather, it leads to a decrease in crop yield due to the loss of nutrients and soil fertility.

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The relationship between organisms in the ecosystem implies that the components are interdependent. This means that living things in an ecosystem rely on each other for survival. For example, plants use sunlight, carbon dioxide, and water to produce food through photosynthesis, and in turn, they release oxygen into the atmosphere which animals need to breathe. Animals also eat plants and other animals for food, and their waste products can provide nutrients for plants to grow. This interdependence creates a delicate balance in the ecosystem, and any changes to one component can have ripple effects on the entire system.

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Heavy rainfall can favour the formation of acid soils because it causes more leaching of base elements from the soil. As rainwater percolates through the soil, it dissolves and carries away minerals such as calcium, magnesium and potassium, which are essential for soil pH buffering. When these base elements are leached out of the soil, the soil pH becomes more acidic. In contrast, in areas with low rainfall, the base elements may accumulate in the soil, buffering the pH and preventing soil acidification. Therefore, heavy rainfall can contribute to the development of acidic soils.

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The correct sequence in which denudation occurs is: Weathering → Erosion → Deposition. Denudation refers to the process of wearing down and stripping away rocks and soil from the Earth's surface. It includes various natural processes such as weathering, erosion, and deposition. Weathering is the first step in denudation, where rocks are broken down into smaller pieces due to physical, chemical, or biological means. These small pieces of rocks are then transported by erosion, which is the second step, to different locations through agents like water, wind, and ice. Finally, deposition, which is the third step, occurs when the eroded rock particles are deposited or laid down in new locations. This can occur when the agents of erosion lose their energy and can no longer transport the rock particles, or when the particles settle in a body of water or other location. Therefore, the correct sequence in which denudation occurs is Weathering → Erosion → Deposition.

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Neptune has the longest orbit around the sun compared to the other planets listed. This is because Neptune is the eighth planet from the sun and is located the farthest from the sun, at an average distance of about 2.8 billion miles (4.5 billion kilometers). It takes Neptune about 164.8 Earth years to complete one orbit around the sun. In contrast, Jupiter, the largest planet in the solar system, has an average distance from the sun of about 484 million miles (778 million kilometers) and takes only about 11.9 Earth years to complete one orbit around the sun.

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A spring is an outlet for underground water. This means that water from underground aquifers or groundwater systems flows up to the surface through a spring. When water from rain, snow or other forms of precipitation seeps into the ground, it collects in underground rock formations or porous soil layers. These underground water reserves are also known as aquifers. When the pressure from the water in the aquifer becomes greater than the pressure holding the water down, the water flows up to the surface through a spring. Springs can be found in various geological settings, but they are most commonly associated with underground water systems. Therefore, a spring is not an outlet for rivers, streams in Karst regions, rain water in limestone regions, or volcanic lakes.

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Jebba, Lokoja, and Onitsha are examples of river ports. A river port is a location on a river that is designated for the loading and unloading of ships and other watercraft. These ports are established in areas where a river is deep enough to allow large vessels to dock and unload their goods. River ports serve as important transportation and trade hubs, connecting inland regions to larger bodies of water and facilitating the movement of goods to different parts of the country or even across international borders.

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Grit is a good example of mechanically formed sedimentary rock. Mechanically formed sedimentary rocks are formed by the accumulation and consolidation of sediment, which is produced by the weathering and erosion of pre-existing rocks. Grit specifically is a type of sedimentary rock that is made up of sand-sized particles of quartz and other minerals, which have been transported by wind or water and deposited in layers. Over time, these layers become compacted and cemented together to form solid rock. Therefore, grit is not formed by volcanic activity, organic processes, or metamorphic processes.

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The predominant action at the upper course of a river is corrosion. This is because the upper course of a river is characterized by steep gradients and high velocity, which leads to the erosion of the riverbed and banks. The force of the water cuts into the rock and soil, wearing it away over time. This process is known as corrosion or hydraulic action. The erosion caused by corrosion leads to the formation of steep-sided V-shaped valleys and gorges in the upper course of a river. The erosion also causes the river to deepen and widen its channel, increasing its capacity to carry water and sediment downstream. As the river flows downstream, transportation and deposition become more dominant processes.

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The density of the upper part of the lithosphere is around 2.7 grams per cubic centimeter (g/cm³). The lithosphere is the solid, outermost shell of the Earth that consists of the crust and the uppermost part of the mantle. The density of the lithosphere varies depending on the composition and thickness of the rock layers that make up the crust and upper mantle. The upper part of the lithosphere, which includes the crust and the uppermost mantle, is composed of lighter rocks, such as granite and basalt, that have a lower density than the rocks found deeper in the mantle. This gives the upper part of the lithosphere a lower overall density of around 2.7 g/cm³.

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The seasonal variation in the volume of water in a river is known as its regime. A river's regime can vary depending on the climate and topography of the region it flows through. In areas with distinct wet and dry seasons, the river's flow will be higher during the rainy season and lower during the dry season. This can be due to increased rainfall and runoff during the wet season or reduced groundwater recharge during the dry season. Understanding a river's regime is important for managing water resources, as it can impact activities such as irrigation, hydropower generation, and transportation. Therefore, the correct option is: regime.

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The important area for lumbering in Nigeria is the Ibadan-Benin-Port Harcourt region. Lumbering is the process of cutting and processing trees into logs, planks, and other forms that can be used for construction and other purposes. The Ibadan-Benin-Port Harcourt region is located in the southern part of Nigeria and is known for its large forest reserves which contain valuable timber species like mahogany, teak, and ebony. The region also has a favorable climate for tree growth and is well-suited for lumbering activities.

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The major pollutants of the environment are substances that contaminate the air, water, and soil and can harm living organisms. Out of the options listed, "domestic cooking" is not a major pollutant of the environment. While burning fossil fuels during cooking can emit pollutants like carbon monoxide and particulate matter, the scale of these emissions is relatively small compared to the other options listed. The other options, including flaring of gas in oil wells, oil spillage, industrial waste products, and combustion from vehicles, can release large amounts of harmful pollutants into the environment. Flaring of gas in oil wells releases greenhouse gases like carbon dioxide and methane, while oil spillage can contaminate waterways and harm wildlife. Industrial waste products can contain hazardous chemicals and heavy metals, while vehicle combustion emits pollutants like nitrogen oxides, carbon monoxide, and particulate matter. All of these can cause significant harm to the environment and human health.

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Jos has a heavier rainfall than the other towns on the same latitude in Nigeria because it is located on the windward side of a plateau. Windward side is the direction from which the wind is blowing and is characterized by upward movement of air, cooling, and condensation of moisture leading to rainfall. Jos is located on the Jos Plateau, which is a highland area with an elevation of about 1,200 meters above sea level. The plateau rises above the surrounding lowlands, and as the moist air from the south passes over the plateau, it is forced to rise, cool, and condense, resulting in rainfall. Thus, Jos receives more rainfall than other towns on the same latitude in Nigeria due to its location on the windward side of a plateau.

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Furniture making is an example of light industry and not heavy industry. Heavy industry involves the production of large-scale machinery, equipment, and materials such as iron and steel, aluminium, ship building, and petroleum refining. Furniture making, on the other hand, is considered a light industry because it involves the production of relatively small and lightweight products such as chairs, tables, and cabinets. Therefore, the correct answer is "furniture making".

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On September 23, all towns in the northern hemisphere experience equal length of day and night. This is because September 23 marks the autumnal equinox, which is one of two days in a year when the tilt of the Earth's axis is neither towards nor away from the sun. This means that the duration of daylight and darkness is almost equal across the entire planet, giving an equal length of day and night in most parts of the world, including the northern hemisphere.

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The vegetation belt in Africa that is usually associated with the tropical continental climate is the Sudan Savanna. The tropical continental climate is characterized by high temperatures and low rainfall, with most of the precipitation occurring in the summer months. The Sudan Savanna is a vegetation belt that is found in the region of Africa where this type of climate prevails. The Sudan Savanna is a transitional zone between the Sahara Desert to the north and the Guinea Savanna to the south. It is characterized by grasses, scattered trees, and shrubs. During the dry season, the vegetation becomes brown and dry, but during the rainy season, it becomes lush and green. The Guinea Savanna and the Tropical Rainforest are associated with higher amounts of rainfall compared to the Sudan Savanna, while the Tropical Monsoon Forest is associated with a climate characterized by distinct wet and dry seasons. The Tropical Desert, on the other hand, is associated with a very low amount of rainfall. Therefore, the correct answer is the Sudan Savanna.

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Igneous rocks contain crystals. When magma or lava cools and solidifies, it forms igneous rocks. The cooling process allows minerals to crystallize, which gives igneous rocks their characteristic texture. The type and size of the crystals depend on the rate of cooling and the composition of the magma or lava. Since igneous rocks are formed from molten material deep within the Earth or on its surface, they do not contain humus, fossils, strata, or polyps.

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Lacustrine plains are formed on the bed of an old lake. A lake is a body of water surrounded by land, and over time, sediments can accumulate at the bottom of the lake. When the lake dries up or drains, the sedimentary deposits left behind form a flat plain. These plains can be found in various parts of the world, and they can be quite extensive. The sedimentary deposits can include a range of materials, such as clay, sand, and silt, which can have economic value. In addition to their economic importance, lacustrine plains can also be ecologically valuable, providing habitat for a variety of plants and animals. Therefore, the correct option is: on the bed of an old lake.

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Neither oak nor cedar are typically found in equatorial, tundra, or desert vegetation due to unsuitable climate conditions. Oak and cedar are commonly found in Mediterranean vegetation, which is characterized by mild, rainy winters and hot, dry summers.

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The statement "is the next planet to the Earth" is not true. Jupiter is not the next planet to Earth. In fact, it is the fifth planet from the sun and is located after Mars and before Saturn.

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A feature of erosion in arid regions is Yardang. Yardangs are elongated, streamlined ridges with steep sides that are aligned with the prevailing wind direction. They are formed by wind erosion of soft rocks, such as sandstone and shale, and are typically found in desert landscapes where there is little vegetation to stabilize the soil. The wind erodes the rock surface, creating a streamlined shape, while the harder rocks that are more resistant to erosion are left standing as ridges. Yardangs can range in size from a few meters to several kilometers long, and they are often found in clusters or fields. They are an important feature of arid landscapes, and they provide valuable information about past climates and the geological history of an area.

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The tropical desert climate is characterized by very low annual rainfall, resulting in arid conditions. The high temperatures and low humidity in this climate result in cloudless skies and frequent dust haze. The very high diurnal range of temperature (i.e. the difference between the day and night temperatures) is also a common feature of the tropical desert climate. However, a very low annual range of temperature is not a characteristic of this climate. In fact, temperatures in tropical deserts can vary widely throughout the year, with hot days and cool nights. Therefore, the correct option is: Very low annual range of temperature.

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A slender, downward growing pinnacle that hangs from a cave roof is called a "stalactite". Stalactites are formed by the deposition of calcium carbonate and other minerals that are left behind by water droplets that fall from the ceiling of a cave. As the water evaporates, it leaves behind tiny amounts of minerals that slowly build up over time, forming the long, slender structures that we call stalactites.

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Crater lakes are most likely to occur in regions of extinct volcanoes. These are the areas where the volcanoes have stopped erupting and have become dormant or extinct. Crater lakes are formed when the crater or caldera of a volcano fills with water. The water in the crater lake may come from precipitation, groundwater, or from streams and rivers that flow into the crater. The water in the crater lake is often deep and clear, with a blue or green tint due to the minerals and other substances that are dissolved in it. Crater lakes are important features of the landscape and can provide habitats for a variety of plant and animal species. They are also popular tourist destinations and are often surrounded by scenic views of mountains and other natural features.

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The option that is not a major problem of economic development in developing countries is "natural resources". Natural resources, such as oil, minerals, and agricultural products, are often considered an advantage for developing countries. The major problems of economic development in developing countries include inadequate capital, technical know-how, transportation facilities, and infrastructure. Inadequate capital refers to the lack of investment and financial resources needed to support economic growth and development. Technical know-how refers to the lack of knowledge and expertise in areas such as science, technology, and engineering, which can hinder the development of industries and new technologies. Transportation facilities refer to the lack of adequate transportation infrastructure, such as roads, railways, and ports, which can limit trade and economic growth. Infrastructure refers to the lack of basic public services, such as water supply, sanitation, and healthcare, which can impact the quality of life and productivity of the workforce.

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The word "shore" is best described as the zone between high and low water levels at the coast. This zone is called the intertidal zone or littoral zone. It is the area that is exposed to air at low tide and covered by water at high tide. The intertidal zone is a unique habitat with a diverse array of organisms, such as crabs, snails, and seaweeds, that have adapted to the constantly changing environment. The shore, or intertidal zone, is an important ecosystem that supports a variety of marine life and is also a popular recreational area for activities such as swimming, fishing, and beachcombing.

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(a) Five causes of flooding

1. Heavy and prolonged rainfall that exceeds the rate of infiltration and river discharge, so the excess water spreads over the land.
2. Overflow of rivers when the volume of water exceeds the capacity of the channel, especially on the flood plain of the lower course.
3. Poor or blocked drainage systems in towns, where drains choked with refuse and silt cannot carry away run-off.
4. Deforestation which removes the vegetation that intercepts rain and promotes infiltration, thereby increasing surface run-off.
5. Coastal storm surges and high tides that drive sea water inland over low-lying coastal land; dam failure or excessive release from dams may be added.

(b) Four ways flooding can be controlled

1. Construction of dams and reservoirs upstream to store excess water and release it gradually.
2. Building of embankments, dykes and levees along river banks to confine the water to the channel.
3. Provision and regular clearing of wide drainage channels to carry away surface water quickly, and control of building on flood plains.
4. Afforestation and reforestation of catchment areas to increase interception and infiltration and reduce run-off; river channels may also be dredged and straightened to speed discharge.

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Give reasons for the following agricultural patterns in Nigeria.

(a) Market gardening is predominantly practised around major urban areas

1. Market gardening produces perishable crops (vegetables, tomatoes, fruits) which must reach the consumer quickly, so nearness to the urban market reduces spoilage.
2. The large urban population provides a ready and high-demand market for fresh produce.
3. Nearness to the city gives access to water (for irrigation), transport and manure/refuse from the town, and reduces transport cost of the bulky, fragile produce.

(b) Lumbering is practised mainly in the high forest belt

1. The high forest belt of the south has heavy rainfall and high temperatures that support dense evergreen tropical forest.
2. It contains large stands of valuable timber trees such as mahogany, iroko, obeche and opepe.
3. The area's rivers and nearness to ports (and sawmills) aid the movement and export of logs.

(c) Rice is cultivated in large quantity in the Middle Belt

1. The Middle Belt has extensive river valleys and fadama (flood plains) with alluvial soils that hold water needed by rice.
2. It has a moderate to heavy rainfall and a long enough wet season suited to rice.
3. There is abundant land and a smaller population, allowing large-scale cultivation, and government support for rice production.

(d) Cattle rearing is important in the Sudan Savanna Belt

1. The belt has extensive grassland that provides natural pasture for grazing.
2. The dry climate and low rainfall keep the area relatively free of the tsetse fly which spreads sleeping sickness (trypanosomiasis) in cattle.
3. The open, gently undulating land and the pastoral tradition of the Fulani favour large-scale herding.

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How each factor affects the climate of Africa.

(a) Latitude

Latitude determines the angle at which the sun's rays strike the earth and hence the amount of heat received. Areas near the equator (low latitudes) receive the sun's rays almost vertically and are therefore hot throughout the year with heavy convectional rainfall. As one moves towards the tropics and higher latitudes, the rays become more slanting, temperatures fall and rainfall becomes seasonal and lower, giving savanna, desert and, in the far north and south, warm temperate (Mediterranean) climates. Latitude thus explains the broadly symmetrical arrangement of climatic belts north and south of the equator.

(b) Ocean currents

Ocean currents affect the temperature and rainfall of coastal areas. Warm currents, such as the warm Mozambique/Agulhas current off south-east Africa and the warm Guinea current, raise coastal temperatures and, by warming the onshore winds, encourage rainfall. Cold currents, such as the Benguela current off the south-west coast and the Canaries current off the north-west coast, lower coastal temperatures and chill the onshore air so that it holds little moisture; this produces aridity and coastal deserts (e.g. the Namib and part of the Sahara) and coastal fogs.

(c) Distance from the sea (continentality)

The sea moderates temperature, so places near the coast have a small annual range of temperature (cool summers, mild winters) and receive more rainfall from moisture-laden sea breezes. Places far inland in the interior of Africa are cut off from the moderating and moistening influence of the sea; they therefore have a large range of temperature (very hot days and cool nights, hot summers and cool winters) and low, unreliable rainfall, giving continental and desert conditions.

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(a) Locations on the outline map of Nigeria

(i) Highlands:

• North-Central (Jos) Highlands around Jos in the centre-north.
• Western Highlands (Yoruba/Western uplands) in the south-west.
• Adamawa Highlands in the east/north-east on the Cameroon border (Gongola/Adamawa area).
• Udi Hills (Udi Plateau) in the south-east near Enugu.

(ii) Rivers: Sokoto (north-west), Gongola (north-east, draining into the Benue), Oshun (south-west) and Anambra (south-east, draining into the Niger).

(b) Four ways the North-Central (Jos) Highlands are of economic importance

1. Mining: the plateau is Nigeria's chief source of tin and columbite, providing minerals for export and revenue.
2. Agriculture: the cool climate favours temperate crops and market gardening (Irish potatoes, vegetables, fruits) and cattle rearing on the grasslands.
3. Hydro-electric power and water supply: the high land and rivers provide sites for dams and are a source of many rivers.
4. Tourism and health resort: the cool, pleasant climate and scenery (e.g. Jos and the Assop Falls) attract tourists and make it a health resort; it also supports forestry.

(c) Four problems limiting the economic development of the region

1. Rugged and steep terrain which hinders the construction of roads, railways and buildings.
2. Derelict land and erosion caused by past tin mining, leaving pits and infertile spoil heaps.
3. Thin, poor soils in parts, and shortage of good farmland.
4. Isolation and inadequate infrastructure, together with communal conflicts, which discourage investment.

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(a) Significance of minerals as an environmental resource

1. Source of energy: fuel minerals such as petroleum, coal and natural gas provide power for industries, transport and domestic use.
2. Raw materials for industry: minerals like iron ore, bauxite, limestone and tin supply the metal, cement and manufacturing industries.
3. Source of foreign exchange and revenue: the export of minerals earns foreign currency and government revenue that finance national development.
4. Employment: mining and related activities provide jobs for many people, both directly and indirectly.
5. Development of infrastructure: mining areas attract roads, railways, electricity and towns.
6. Support for other sectors: minerals such as limestone and phosphate provide materials for construction and fertiliser for agriculture.

(b) Three major problems resulting from the exploitation of mineral resources

1. Land degradation and destruction of the landscape: opencast mining, quarrying and dredging leave pits, spoil heaps and derelict land that is unfit for farming or building.
2. Environmental pollution: mining pollutes air with dust and fumes, and pollutes rivers and soil with chemicals and oil spillage, harming plants, animals and human health.
3. Displacement of people and social disruption: communities are forced off their land, farmland is lost, and rapid growth of mining camps brings overcrowding and social vices; rapid depletion of a non-renewable resource is a further problem.

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(a)(i) The three climatic belts of the Greek system

1. The Torrid Zone (hot/tropical belt).
2. The Temperate Zones (warm to cool belts, north and south).
3. The Frigid Zones (cold/polar belts, north and south).

(a)(ii) Basis of the classification

The Greek classification is based on latitude and the amount of heat (temperature) received from the sun. The belts are bounded by the tropics and the polar circles according to the angle of the sun's rays.

(b) One characteristic of each belt

1. Torrid Zone: lies between the Tropic of Cancer and the Tropic of Capricorn and is hot throughout the year with the sun overhead at some time.
2. Temperate Zone: lies between the tropics and the polar circles and has moderate temperatures with distinct warm and cool seasons.
3. Frigid Zone: lies between the polar circles and the poles and is very cold throughout the year with long, dark winters.

(c) Three advantages of Koppen's classification over the Greek system

1. Koppen uses both temperature and rainfall, whereas the Greek system uses temperature (latitude) alone, so Koppen gives a fuller picture of climate.
2. Koppen's boundaries are based on natural vegetation, so the climatic regions correspond to real plant and crop distributions on the ground.
3. Koppen's classification is more detailed and precise, recognising many climatic types with defined values, rather than only three broad zones fixed by latitude.

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(a) Outline map of Nigeria showing the savanna belts and one important town in each

Nigeria's savanna belts run in broadly east–west bands that succeed one another from south to north as rainfall declines. The map below shows the three belts and one representative town in each:

• Guinea Savanna (the southernmost, widest belt) — town: Ilorin (also Kaduna, Makurdi).
• Sudan Savanna (the middle belt) — town: Kano (also Sokoto).
• Sahel Savanna (the far north-eastern belt) — town: Maiduguri (also Nguru).

(b) Three vegetation characteristics of the Guinea Savanna belt

1. Presence of tall grasses. The ground is dominated by tall, coarse grasses that may reach about 3 metres in height by the end of the wet season.
2. Presence of tall, scattered trees. Fairly tall deciduous trees such as the locust bean and shea-butter tree stand scattered among the grasses, giving an open woodland (parkland) appearance. It is the wettest and most wooded of the savanna belts.
3. Trees shed their leaves in the dry season. The trees are drought- and fire-resistant, with thick bark, and shed their leaves during the long dry season to reduce water loss.

(By contrast, the Sudan Savanna has shorter grasses and shorter, thornier, more scattered trees such as acacia, while the Sahel Savanna carries only sparse short grasses and stunted thorn scrub.)

(c) Relationship between vegetation and rainfall in the savanna belts

The vegetation of the savanna is closely controlled by the amount and duration of rainfall, both of which decrease steadily from south to north. The main points of the relationship are:

1. Rainfall decreases from the Guinea Savanna in the south towards the northern (Sahel) limit; correspondingly the vegetation changes from tall grasses and numerous trees to short grasses and sparse thorn scrub.
2. The rainy season lasts longer in the Guinea Savanna than in the Sahel Savanna, so plants there enjoy a longer growing period, grow taller and remain green for more of the year.
3. The low rainfall of the Sahel (only about 20 cm falling to as little as 7 cm a year in the far north) is too little to support tall growth, so it leads to the stunted, thorny growth of trees and grasses.
4. The arrival of the rains marks the start of grass growth (the greening of the savanna), and the length of the dry season determines how long the grasses dry up and the trees stand leafless.

Thus the density, height and greenness of the savanna vegetation diminish in step with the declining rainfall from the Guinea belt in the south to the Sahel belt in the north.

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(a) Five functions which urban centres perform for rural areas

1. Market function: towns provide markets where rural producers sell their farm produce and buy manufactured goods.
2. Provision of manufactured goods and services: urban industries supply farm inputs (fertiliser, tools, machinery) and consumer goods needed in the villages.
3. Administrative and political function: towns house government offices, courts and local administration that serve the surrounding rural districts.
4. Educational and health services: secondary schools, colleges, and hospitals in towns serve the rural population.
5. Financial and commercial services: banks, insurance and credit facilities in towns provide loans and savings for rural farmers and traders.
6. Employment and processing: urban factories process rural raw materials and offer jobs to rural migrants (also transport and communication hub).

(b) Four problems that may limit the performance of these functions

1. Poor transport links: bad roads and inadequate transport make it difficult to move goods and people between town and country.
2. Inadequate infrastructure and finance: shortage of funds, electricity and water limits the services the town can offer.
3. Rapid urban growth and overcrowding: pressure of a swelling population strains urban facilities so they cannot adequately serve rural areas.
4. Poverty and low purchasing power of rural people: low rural incomes limit demand for urban goods and services; political instability and poor planning may be added.

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(a) Four ways a fall in birth rate can be beneficial to a country

1. Reduced pressure on resources: fewer births ease the demand on food, land, water and housing.
2. Lower dependency burden: fewer children to be catered for allows more savings and investment in the economy.
3. Improved standard of living: national income is shared among fewer people, so income per head rises.
4. Less pressure on social services: fewer schools, hospitals and other facilities are needed, so existing ones serve the people better.
5. Reduced unemployment: a slower growing labour force is easier to absorb into available jobs.

(b) Four problems that can arise from a fall in birth rate

1. Ageing population: the proportion of old people rises while the number of young people falls.
2. Shortage of labour: a smaller working population reduces the supply of workers for farms, industries and services.
3. High old-age dependency: the working population must support a large number of retired and aged people.
4. Reduced market and slower economic growth: a shrinking population means a smaller home market for goods and services and a fall in national output; the country may also weaken in defence and manpower.

(c) Four ways the birth rate can be increased

1. Payment of family allowances and child benefits to encourage couples to have more children.
2. Grant of maternity leave, free maternal and child health care and other incentives to mothers.
3. Discouraging or restricting the use of family-planning and birth-control methods.
4. Encouraging early marriage and larger families through public campaigns, and reducing the cost of raising children (free education, tax relief).

Detalles de la respuesta

(a) Four factors that have favoured plantation agriculture in East Africa

1. Favourable climate: the highlands and coast provide the warm to cool temperatures and reliable rainfall suited to crops such as tea, coffee, sisal and sugar cane.
2. Fertile soils: the deep volcanic soils of the East African highlands are rich and suitable for tree and cash crops.
3. Availability of land and cheap labour: large areas of suitable land and a supply of cheap local labour make large-scale estate farming possible.
4. Capital, transport and market: foreign (colonial) capital and management, railways and roads to the ports (e.g. Mombasa), and a ready overseas market for the produce encouraged the establishment of plantations.

(b) Four ways plantation agriculture is important to the economy

1. Foreign exchange: export crops such as tea, coffee and sisal earn foreign currency.
2. Employment: plantations and processing factories provide jobs for many workers.
3. Raw materials and processing industries: they supply raw materials that support agro-based industries (tea factories, sugar mills).
4. Infrastructure and revenue: they generate government revenue and attract roads, railways, health and social services to rural areas.

(c) Four problems facing plantation agriculture in the region

1. Fluctuation of world prices of the export crops, which makes income unstable.
2. Pests and diseases that attack the crops and reduce yields.
3. Over-dependence on one or few crops (monoculture), which exhausts the soil and exposes the economy to risk.
4. Shortage of labour and capital, and competition from other producing regions; unreliable rainfall/drought and land-tenure disputes may be added.

Detalles de la respuesta

(a) Sketch map of Africa

The sketch map below shows the two highlands, one important river rising from each, one inland drainage basin, one artificial lake and one lagoon coast, each clearly named.

Reading the map:

• (i) The Fouta Djallon (Fouta Mallon) Highlands lie in Guinea, in the far west of Africa, and the Cameroon Highlands lie along the Nigeria–Cameroon border, at the inner corner of the Gulf of Guinea.
• (ii) The River Niger takes its source from the Fouta Djallon Highlands, and the River Benue takes its source from the Adamawa/Cameroon Highlands (the two join before entering the sea through the Niger Delta).
• (iii) The Chad Basin (drained inward to Lake Chad) is the important inland drainage basin.
• (iv) Lake Volta in Ghana is the artificial lake.
• (v) The Gulf of Guinea coast (from Côte d'Ivoire through Ghana, Togo and Benin to Nigeria) is the lagoon coast.

(b) Three ways river basins are important to the economy of Africa

1. Agriculture and irrigation: the fertile alluvial soils and reliable water of river basins (e.g. the Nile and Niger basins) support irrigation and intensive crop farming, which feeds the population and provides export earnings.
2. Settlement, water supply and fishing: river basins provide good sites for settlement and towns, supply water for domestic and industrial use, and support inland fisheries that give food and income.
3. Transport and hydro-electric power: navigable stretches serve as cheap communication and trade routes, while the rivers provide dam sites that generate hydro-electric power for homes and industry (e.g. Akosombo on the Volta and Kainji on the Niger).

(c) Three major characteristics of the coastline of Africa

1. It is smooth and regular with few indentations, so it has relatively few deep bays or natural harbours and few good natural ports.
2. It has several estuaries and delta coasts, for example the estuary sections near Togo and the great deltas of the Nile and the Niger.
3. Long stretches, especially along the Gulf of Guinea, are lagoon coasts fringed by sand bars, spits and mangrove swamps, while parts of the East African coast are bordered by coral reefs.

Detalles de la respuesta

None

Detalles de la respuesta

(a) Five factors to consider in the location of a cement factory

1. Availability of raw materials: the factory must be sited close to deposits of limestone (the main raw material) together with clay/shale and gypsum, because these are bulky and weight-losing.
2. Source of power/fuel: cement manufacture uses much energy for the kilns, so nearness to coal, gas or electricity supply is important.
3. Water supply: an adequate supply of water is needed for the manufacturing process and cooling.
4. Transport facilities: good roads and railways are needed to bring in fuel and take the heavy, finished cement to markets.
5. Nearness to market: siting near large urban and building markets reduces the cost of distributing the heavy product.
6. Availability of labour and land: a large flat site and a supply of skilled and unskilled workers are required; capital is also considered.

(b) Three problems facing cement factories in Tropical Africa

1. Inadequate and unreliable power supply: frequent electricity failures disrupt the energy-intensive kiln operations and raise costs.
2. Poor transport network: bad roads and limited railways make it costly to move fuel to the factory and cement to distant markets.
3. Shortage of capital, skilled manpower and spare parts: heavy dependence on imported machinery, foreign experts and imported fuel, together with obsolete plant and low local demand in some areas, limits production.

Detalles de la respuesta

(a) Interdependence in trade between Nigeria and Britain

The trade between the two countries is based on the exchange of goods that each needs from the other, so that neither is self-sufficient.

1. Nigeria exports primary products (crude oil, cocoa, groundnut, rubber, timber, hides and skins) which Britain needs as raw materials for her industries and as food.
2. Britain exports manufactured goods (machinery, motor vehicles, chemicals, textiles, electrical goods) which Nigeria needs but does not produce in sufficient quantity.
3. Britain provides technical services, capital and expertise for Nigerian industries and projects, while Nigeria provides a large market for British goods.
4. Long historical, colonial and Commonwealth ties, a common language and existing business links bind the two economies together.

(b) Four factors that may limit this trade

1. Long distance between the two countries raises transport and freight costs.
2. Competition from other trading partners such as China, the USA and the European Union.
3. Trade restrictions such as tariffs, quotas and foreign-exchange controls imposed by either country.
4. Similarity/limited range of exports and fluctuation in world prices of Nigeria's primary products, which reduces her earnings and buying power; political and policy changes may be added.

(c) Three ways the trade can be improved

1. Reduction or removal of trade barriers (lower tariffs and easier exchange controls) through trade agreements.
2. Improvement of transport and port facilities to lower the cost and time of moving goods.
3. Diversification and improvement of the quality of Nigeria's exports so that they meet British standards and demand; strengthening of trade missions and credit facilities may be added.

Detalles de la respuesta

(a) Sketch map of Africa showing named mineral areas and their towns

The sketch map below shows two areas important for a named fuel mineral (crude oil) and two areas important for a named metallic mineral (gold), each pair lying in a different country, together with one major town in each area.

(i) Fuel mineral - Crude Oil (Petroleum)

Area	Country	Major town
Niger Delta	Nigeria	Port Harcourt
Hassi Messaoud	Algeria	Ouargla

(ii) Metallic mineral - Gold

Area	Country	Major town
Witwatersrand (Rand)	South Africa	Johannesburg
Obuasi	Ghana	Kumasi

(iii) The major town lying in each area is shown on the map and in the tables above: Port Harcourt (Niger Delta), Ouargla (Hassi Messaoud), Johannesburg (Witwatersrand) and Kumasi (Obuasi).

(b) Four problems facing mining in Africa

1. Inadequate capital. Mining requires very large sums of money to prospect, sink shafts, buy machinery and process the ore; most African countries lack this capital and depend on foreign investors.
2. High cost of production. Deep-seated ores, expensive imported machinery, spare parts and fuel make the cost of extracting and processing minerals very high.
3. Inadequate skilled labour. There is a shortage of trained geologists, mining engineers and technicians, so expatriates must be hired at great expense.
4. Fluctuation of mineral prices. Prices of minerals on the world market rise and fall sharply, making incomes unstable and long-term planning difficult.

Other acceptable problems: poor transport and inaccessibility of mining sites, inadequate electric power, and environmental degradation such as land pollution and derelict land.

Detalles de la respuesta

(a) Locations on the outline map of Nigeria

• Eastern Highlands (Obudu-Oban-Mambilla uplands) in the south-east/east on the Cameroon border - river: Cross River; town: Ogoja / Obudu.
• Eastern Scarplands (Enugu-Nsukka-Udi escarpment) in the south-east - river: Anambra (or Imo); town: Enugu.
• Chad Basin in the north-east - river: Yobe (Komadugu); town: Maiduguri.

(b) The Eastern Highlands

(i) Population and settlement

The Eastern Highlands are generally sparsely populated because of the rugged, mountainous relief and difficult access. Settlements are small and scattered, sited in the valleys and on gentler slopes and lower footslopes; density is low compared with the surrounding lowlands, though the cooler climate has encouraged some settlement and a tourist/ranch centre at Obudu.

(ii) Natural resources

The region has dense forests providing timber, fertile volcanic and upland soils, abundant rainfall and rivers offering water and hydro-power potential, cool upland grassland suitable for grazing, and scenic mountain landscapes that are a resource for tourism.

(iii) Economic activities

The main activities are farming (food crops, plantation tree crops and market gardening in the cool uplands), cattle rearing and ranching (e.g. Obudu Cattle Ranch), lumbering in the forests, and a growing tourism industry attracted by the cool climate and scenery; trade and small-scale processing also take place.

Detalles de la respuesta

(a) Four ways water transportation is important in international trade

1. Carriage of bulky and heavy goods: ships can carry large quantities of heavy or bulky cargo (crude oil, timber, grains, machinery) that other means cannot handle economically.
2. Cheapest means over long distances: water transport has the lowest cost per tonne-kilometre, making distant trade profitable.
3. Connects countries and continents: oceans provide natural highways linking producing and consuming nations across the world.
4. Large carrying capacity: a single vessel can move enormous volumes at once, so world trade in large tonnages is possible.

(b) Four limitations of water transportation

1. It is slow compared with air and even road transport, so it is unsuitable for perishable and urgent goods.
2. It is restricted to coastlines and navigable waterways; it cannot reach inland or landlocked areas directly.
3. It is affected by weather and natural hazards such as storms, fog, ice and shallow or silted channels.
4. It requires costly port facilities and large capital for harbours, ships and dredging.

(c) How the limitations can be overcome

1. Link with other transport modes: connect ports to inland areas by good roads, railways and pipelines so goods reach the interior.
2. Dredging and canal construction: deepen and widen channels, build canals and locks, and construct artificial harbours to improve navigation.
3. Use of modern technology: equip ships and ports with radar, weather forecasting and navigational aids to reduce hazards; provide modern cargo-handling to speed up loading.
4. Provide adequate finance and maintenance of ports and vessels, and use faster and specialised ships (container and refrigerated vessels).

Detalles de la respuesta

(a) Outline map of West Africa showing three ECOWAS member countries and their capitals

The three member countries of ECOWAS shown on the map above, together with their capital cities, are:

(Any three of the fifteen ECOWAS states are acceptable, e.g. Cote d'Ivoire - Yamoussoukro; Mali - Bamako; Sierra Leone - Freetown; Togo - Lome; Benin - Porto Novo.)

(b) Three objectives of ECOWAS

1. Promotion of trade and economic cooperation - to increase and strengthen trade among member states and to promote cooperation and development in economic activity throughout the sub-region.
2. Free movement of persons, goods, services and capital - to remove barriers so that citizens, goods and services can move freely across the borders of member countries.
3. Economic integration and a higher standard of living - to work towards a common market and eventually a single currency, and to raise the standard of living of the peoples of the sub-region while maintaining peace and stability.

(c) Three factors that have limited the full attainment of these objectives

1. Language barrier and differences in colonial background - the members are split among English, French and Portuguese speaking states, which hinders communication, negotiation and full integration.
2. Strong colonial ties - many members remain closely linked economically and politically to their former colonial masters in Europe, so they trade more with those countries than with their West African neighbours, weakening intra-regional cooperation.
3. Similarity of economic activities and products - most member states produce and export the same primary agricultural and mineral products, so there is little to exchange among them and much competition rather than complementary trade.

Detalles de la respuesta

(a)(i) Well labelled diagram of the internal structure of the earth

The earth is made up of a series of concentric layers. Working from the outside inwards these are the crust, the mantle, the outer core and the inner core, separated by the Mohorovičić discontinuity (Moho) between crust and mantle and the Gutenberg discontinuity between mantle and core.

(a)(ii) Distinguishing characteristics of one layer (the crust)

Taking the crust (the outermost layer shown in the diagram) as the chosen layer, its distinguishing characteristics are:

• It is the thinnest and outermost layer, about 6–10 km thick beneath the oceans and up to about 35–70 km thick beneath the continents.
• Its upper (continental) part forms the continents. It is built mainly of granite and is rich in silica and aluminium, so it is called SIAL. It is the lighter part, with a density of about 2.7 g/cm³.
• Its lower part forms the ocean floor. It is built mainly of basalt and is rich in silica, iron and magnesium, so it is called SIMA. It is denser, with a density of about 3.0 g/cm³.
• It is solid rock and is the layer on which we live, containing the soil, rocks and mineral resources.
• It has the lowest temperature and density of all the layers, and it rests on the mantle at the Moho discontinuity.

(b) Importance of the hydrosphere to man

The hydrosphere is the total mass of water on, under and above the surface of the earth (oceans, seas, rivers, lakes, groundwater and water vapour). Its importance to man includes:

• It provides fresh water for drinking, domestic use, irrigation of farmland and for industrial processes.
• Oceans, seas, rivers and lakes serve as cheap routes for water transportation of people and goods.
• It is a source of food such as fish and other sea foods, and of minerals like salt and petroleum.
• Fast-flowing and dammed water is used to generate hydro-electric power (H.E.P.).
• It regulates climate and drives the water cycle that brings rainfall to the land.
• Water bodies are used for recreation, tourism and fishing, which provide employment and income.

Detalles de la respuesta

(a) Economic importance of oceans to man

1. Source of food: oceans provide fish and other sea foods; fishing grounds such as those off the coast of West Africa support the fishing industry.
2. Transportation: oceans are cheap natural highways for international trade; ships carry bulky goods across the Atlantic between Africa, Europe and America.
3. Source of minerals: petroleum and natural gas are obtained from the continental shelf (e.g. Gulf of Guinea), and common salt is obtained by evaporating sea water.
4. Generation of power: tidal and wave energy can be harnessed to produce electricity.
5. Tourism and recreation: beaches and coastal resorts attract tourists and provide income, for example along the Mediterranean coast.
6. Source of fresh water: sea water is desalinated to provide fresh water in dry regions such as North Africa and the Middle East.
7. Influence on climate: oceans and their currents moderate temperatures and bring rain-bearing winds that support agriculture.

(b) A warm current in the North Atlantic and factors responsible for its movement

Selected current: the Gulf Stream / North Atlantic Drift, a warm current flowing from the Gulf of Mexico north-eastward across the Atlantic towards north-west Europe.

Factors responsible for its movement:

1. Prevailing winds: the trade winds drive the water westward across the tropics, and the westerlies then push the warm water north-eastward towards Europe.
2. Rotation of the earth (Coriolis force): deflects the moving water to the right in the Northern Hemisphere, guiding it into a clockwise circulation.
3. Differences in water temperature and density: warm, lighter equatorial water flows towards the colder, denser polar water, setting up movement.
4. Differences in salinity: variations in salt content cause density differences that help drive the current.
5. Shape of the coastline and ocean basin: the outline of the American and African coasts deflects and channels the flow of the current.

Detalles de la respuesta

None