WAEC SSCE - Geography - 1991

Détails de la réponse

Détails de la réponse

Détails de la réponse

The most critical element in an ecosystem is energy flow within the system. An ecosystem is a community of living organisms and their physical environment, which interact with each other to form a functional unit. The ecosystem is sustained by the flow of energy, which is captured by producers (plants) through photosynthesis and then transferred to consumers (animals) through feeding. Energy flow is critical to the functioning of an ecosystem because all living organisms require energy to carry out their metabolic processes. Without energy flow, the ecosystem would collapse, and all the organisms in it would die. While growth per day, the number of species, the extent of area covered, and the location of the ecosystem are all important factors, they are ultimately dependent on the flow of energy. For example, the growth of plants and the survival of animals depend on the availability of energy in the form of food. Similarly, the number and diversity of species in an ecosystem depend on the availability of energy and nutrients. Therefore, energy flow is the most critical element in an ecosystem because it is essential for the survival and functioning of all living organisms within the ecosystem.

Détails de la réponse

The Isoberlina tree is characteristic of the Guinea savanna region in Nigeria. Guinea savanna is a transitional zone between the tropical rainforest and the arid Sahel region, and it is characterized by a mixture of grassland and woodland with scattered trees. The Isoberlina tree is a deciduous tree that is well adapted to the Guinea savanna region. It grows in association with other savanna trees such as the shea tree, locust bean tree, and acacia trees. The Isoberlina tree is an important source of firewood, charcoal, and timber, and its leaves are used for medicinal purposes. It is also an important food source for wildlife, especially during the dry season when other vegetation is scarce.

Détails de la réponse

Détails de la réponse

The environmental hazard that has been paired with the wrong factor is "Floods and human factor only." Floods are not caused by human factors alone. Floods can also be caused by natural factors like heavy rainfall, snowmelt, storm surges, and tsunamis. Human factors can contribute to floods by altering the natural landscape through activities like deforestation, construction, and urbanization. However, natural factors still play a significant role in the occurrence of floods. To summarize, floods are not solely caused by human factors, but rather by a combination of both natural and human factors.

Détails de la réponse

The product of chemical weathering is a change in the chemical composition of rocks and minerals, resulting in the formation of new substances. Therefore, the answer to the question would be one of the options that is a result of chemical weathering. Among the options listed, the product of chemical weathering is "Grike." Grike is a solution hollow formed by the chemical weathering of limestone bedrock. As water flows through the cracks and fissures in the rock, it dissolves the rock's calcium carbonate and creates openings and cavities called grikes. Therefore, the correct answer to the question is "Grike."

Détails de la réponse

The most important cash crop in the irrigated Nile Basin is cotton. Cotton is a major cash crop in the Nile Basin due to its importance in the textile industry and the high demand for cotton products globally. The Nile Basin region has suitable climatic conditions for cotton cultivation, with sufficient water resources from the river Nile and its tributaries, making it an ideal crop for irrigation. Cotton cultivation in the Nile Basin is an important economic activity, providing employment opportunities for millions of people in the region, and contributing significantly to the economies of countries such as Egypt and Sudan. The region also produces other crops such as wheat, sugarcane, and groundnuts, but cotton remains the most important cash crop due to its economic value and high demand in the global market.

Détails de la réponse

Détails de la réponse

Détails de la réponse

Détails de la réponse

When a plateau is enclosed by fold mountains it is called an intermontane plateau. This type of plateau is usually formed due to tectonic activities where the plateau is lifted up by folding and faulting of the earth's crust. The fold mountains that enclose the plateau act as natural boundaries, and the plateau may have a flat or undulating surface. Intermontane plateaus are often rich in minerals due to their geological formation and can be found in various parts of the world, including the Rocky Mountains in North America and the Tibetan Plateau in Asia.

Détails de la réponse

Transportation helps economic development through all the options given except the distribution of population. Transportation facilitates the movement of people and goods from one place to another, which in turn leads to increased economic activity and development. With transportation, people can travel to new places to find work or start businesses, and goods can be transported to different markets, promoting national and international trade. Transportation also plays a crucial role in the diffusion of ideas and technology, as it allows for the transfer of knowledge and innovation across regions and countries. Additionally, transportation helps promote national integration by connecting different regions of a country and allowing people to move freely between them. However, transportation may not necessarily contribute to the distribution of population, as people tend to migrate to areas with better economic opportunities, regardless of whether there is adequate transportation infrastructure or not. Therefore, transportation may not directly impact the distribution of population in a significant way.

Détails de la réponse

Détails de la réponse

Détails de la réponse

Pluto has the longest orbit around the Sun compared to the other four options given. It takes Pluto approximately 248 Earth years to complete one orbit around the Sun. In contrast, Earth takes about 365 days to complete one orbit around the Sun. This means that Pluto takes almost 248 times longer than Earth to complete one orbit around the Sun. So, Pluto has the longest orbit around the Sun among the five options provided.

Détails de la réponse

Détails de la réponse

Détails de la réponse

To calculate the population density, we divide the population by the land area: Population density = Population / Land area Substituting the given values, we have: Population density = 6,175,000 / 17,700 Population density = 348.87 people per km² (rounded to the nearest whole number) Therefore, the approximate population density per km² is 349 people. Answer option (iv) is the correct answer.

Détails de la réponse

The liquid portion of the earth is referred to as the "hydrosphere". The hydrosphere is the part of the Earth's surface where water exists, including oceans, seas, rivers, lakes, and groundwater. It is composed of all the water on the planet, which makes up about 71% of the Earth's surface. The other major spheres of the Earth are the atmosphere, which is the layer of gases that surrounds the planet; the lithosphere, which is the solid outer layer of the Earth's surface; and the biosphere, which is the part of the Earth where life exists. Therefore, the hydrosphere refers specifically to the liquid portion of the Earth, while the other spheres refer to different aspects of the planet.

Détails de la réponse

Détails de la réponse

A conurbation refers to a region that comprises several towns or cities that have grown and expanded to the point where their suburbs have merged, creating a single large urban settlement. Essentially, it's a densely populated area made up of multiple cities and towns that are physically and economically interconnected. So, option B, "several towns whose suburbs have expanded and merged to form an urban sprawl," best describes a conurbation.

Détails de la réponse

Détails de la réponse

A conurbation is a term used to describe a region or area where several towns and their suburbs have expanded and merged together, forming a continuous urban sprawl. It is characterized by a high population density and economic integration, with people living and working across different towns and cities within the area. A conurbation may consist of two or more towns joined together, but still retaining their distinct identities, or it may be a continuous belt of urban settlements. Essentially, a conurbation is a large metropolitan area formed by the merging of several smaller towns and suburbs.

Détails de la réponse

The major relative advantage of road transportation over rail is that it provides door-to-door service. Unlike rail transportation, which is limited to specific stations and depots, road transportation can deliver goods and passengers directly to their desired destination, making it a more convenient and flexible mode of transportation. This also allows for quicker delivery times and more personalized service.

Détails de la réponse

Détails de la réponse

Détails de la réponse

Détails de la réponse

The aim of ECOWAS (Economic Community of West African States) is to promote economic integration among its member states in West Africa. The organization seeks to achieve this through the establishment of a common market, harmonization of economic policies, and the removal of trade barriers among member states. Additionally, ECOWAS aims to improve political stability and security in the region, promote cultural and educational cooperation, and provide a common fund to help the needy. Therefore, the option that is not one of the aims and objectives of ECOWAS is "encourage emigration of people in all member states."

Détails de la réponse

Détails de la réponse

Détails de la réponse

Détails de la réponse

Détails de la réponse

Détails de la réponse

The monthly range of temperature is the difference between the highest and lowest daily temperatures for the month. This means that for each day of the month, the highest temperature and the lowest temperature are recorded. The range of temperature for the month is then calculated by subtracting the lowest temperature from the highest temperature for the month. For example, if the highest temperature recorded during the month was 30°C and the lowest temperature recorded was 10°C, the range of temperature for the month would be: 30°C - 10°C = 20°C Therefore, the correct answer is "differences between the highest and lowest daily temperature for the month."

Détails de la réponse

Harmattan is the option that does not intervene in the natural environment. Harmattan is a dry and dusty trade wind that blows from the Sahara desert over West Africa towards the Gulf of Guinea during the winter months. It is a natural occurrence caused by atmospheric pressure differences between the Sahara and the Gulf of Guinea. Unlike the other options listed, harmattan does not involve human activities that have an impact on the natural environment. Construction works, land reclamation, farming, and pollution are all human activities that can have a negative impact on the environment.

Détails de la réponse

Détails de la réponse

Man (human activities) is the factor that least affects the distribution of vegetation. While humans can certainly have an impact on the environment and ecosystems through activities like deforestation, land-use changes, and pollution, their impact is generally localized and can be limited in scale. In contrast, the other factors listed - rainfall, wind, soil, and temperature - are all natural factors that have a significant influence on the distribution of vegetation. For example, different types of vegetation are adapted to specific temperature ranges, rainfall levels, and soil conditions. Wind can also affect vegetation distribution by drying out plants or damaging them physically. Therefore, while humans can have an impact on vegetation distribution, their impact is generally less significant than natural factors such as rainfall, wind, soil, and temperature.

Détails de la réponse

The greatest hydro-electric power potential in Nigeria is found in the Niger-Benue trough. This is because the Niger-Benue trough is a geological feature that runs through the center of Nigeria, and it is characterized by several large rivers and reservoirs that can be used for hydro-electric power generation. The major rivers in this trough include the Niger, Benue, and Kaduna rivers, which have the potential to generate a significant amount of electricity. Additionally, there are several dams and hydro-electric power plants located in this region, such as the Kainji, Jebba, and Shiroro dams, which are some of the largest in Nigeria. Therefore, the Niger-Benue trough has the greatest potential for hydro-electric power generation in Nigeria.

Détails de la réponse

Alumina is the product of the aluminum industry and not the chemical industry. Therefore, the correct answer is Alumina. The chemical industry is responsible for producing a wide range of products, including synthetic rubber, dye, fertilizers, and plastics. These products are made through a variety of chemical processes and are used in a wide range of applications across different industries. Alumina, on the other hand, is produced through the refining of bauxite ore and is primarily used in the production of aluminum.

Détails de la réponse

Water pollution is not caused by sand filling. Sand filling, which involves the placement of sand in a specific area to fill in gaps or create land, does not necessarily involve the discharge of pollutants into the water. However, the other options listed - increased silt load, sewage disposal, industrial effluent, and mineral workings - can all contribute to water pollution. Increased silt load can lead to sedimentation, blocking sunlight, and reducing oxygen levels, which can harm aquatic life. Sewage disposal can introduce harmful bacteria and viruses into the water, which can cause diseases in humans and aquatic life. Industrial effluent can contain toxic chemicals and heavy metals that can damage aquatic ecosystems and affect the health of people who consume the contaminated water. Mineral workings can produce acidic runoff that can pollute nearby streams and rivers, killing fish and other aquatic organisms.

Détails de la réponse

Johannesburg is the most important town for the mining of gold in Africa. Johannesburg is located in South Africa and is known as the City of Gold because of its rich history and connection to gold mining. It was founded in the late 1800s after gold was discovered in the area, and it quickly became a center for gold mining and related industries. Today, Johannesburg is still an important center for gold mining in Africa, with several large gold mines located in the area.

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

(a)

1. The Sahel region, which includes parts of Mauritania, Mali, Niger, Chad, and Sudan, experiences less than four months of rainfall annually.
2. The coastal region of West Africa, including countries like Nigeria, Ghana, and Ivory Coast, experiences rainfall all year round.
3. The high pressure belt in January is located over the Sahara desert and the Sahel region.

(b)

The three reasons for the length of the rainy season in the Sahel region (area with less than four months of rainfall annually) are:

1. The Intertropical Convergence Zone (ITCZ): During the rainy season, the ITCZ, a low-pressure zone where the trade winds converge, moves southwards towards the Sahel region. This brings moist air, which leads to rainfall.
2. Monsoon winds: The Sahel region is influenced by the West African monsoon winds, which bring moist air from the Atlantic Ocean. These winds help to sustain the rainy season.
3. The Gulf of Guinea: The warm waters of the Gulf of Guinea also contribute to the length of the rainy season in the Sahel region. The warm waters evaporate, and the moisture is carried inland by the monsoon winds.

(c)

The three problems that rainfall may pose to agriculture in the coastal region of West Africa (area with rainfall all year round) are:

1. Soil erosion: Heavy rainfall can cause soil erosion, which can wash away fertile topsoil and leave the land less productive. This is a major problem in areas with steep slopes and poor soil structure.
2. Flooding: Excessive rainfall can also cause flooding, which can destroy crops and homes, and lead to the loss of life. Flooding can also cause soil saturation, which can lead to the loss of soil nutrients and make it difficult for crops to grow.
3. Plant diseases: Rainfall can increase the incidence of plant diseases, which can reduce crop yields. Moisture-loving fungi and bacteria thrive in wet conditions and can infect crops, leading to poor quality and reduced yields.

Détails de la réponse

(a)
(i) Two ECOWAS member countries along the coast:
- Ghana
- Cote d'Ivoire
(ii) Two ECOWAS member countries in the interior:
- Burkina Faso
- Mali
(iii) The capital of each of the countries:
- Ghana: Accra
- Cote d'Ivoire: Yamoussoukro (official capital) and Abidjan (economic capital)
- Burkina Faso: Ouagadougou
- Mali: Bamako

(b) Benefits derived from ECOWAS membership:
One of the countries shown on the map is Burkina Faso, and six benefits derived from its membership of ECOWAS are:
1. Increased regional trade: ECOWAS promotes free movement of goods and services among its member states, which has facilitated trade between Burkina Faso and other member countries.
2. Economic development: ECOWAS offers a platform for regional economic cooperation and integration, which has helped to stimulate economic growth in Burkina Faso.
3. Regional peace and security: ECOWAS has played a key role in maintaining peace and stability in West Africa, including Burkina Faso, through its peacekeeping missions and conflict resolution efforts.
4. Improved infrastructure: ECOWAS has initiated and funded various infrastructure development projects in Burkina Faso, such as roads, bridges, and energy projects.
5. Increased investment: ECOWAS membership has created opportunities for Burkina Faso to attract more foreign investment from other member states, which has helped to boost the country's economy.
6. Regional cooperation: ECOWAS provides a platform for Burkina Faso to cooperate with other member states on issues of common interest, such as environmental protection, health, and education. This has helped to promote regional integration and solidarity among member states.

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

(a)

(i)

• Diamond: The area around the town of Koidu in Sierra Leone
• Petroleum: The Niger Delta region in Nigeria
• Gold: The Ashanti region in Ghana

(ii)

• Koidu: located in the Kono District in Sierra Leone
• Port Harcourt: located in the Niger Delta region in Nigeria
• Obuasi: located in the Ashanti region in Ghana

(iii)

• Diamond: Koidu to the port of Freetown in Sierra Leone
• Petroleum: Port Harcourt to the Bonny Terminal in Nigeria
• Gold: Obuasi to the port of Takoradi in Ghana

(b)

One method of mining gold in the Ashanti region of Ghana is the underground mining method. This involves the sinking of shafts through the ground and the creation of tunnels to reach the gold ore. Miners use drilling equipment to drill holes into the rock, which are then filled with explosives to break up the rock and make it easier to extract the gold. The broken rocks are then loaded onto carts and transported to the surface for processing.

(c)

Four problems associated with mining in West Africa are:

• Environmental degradation: Mining activities can lead to soil erosion, deforestation, water pollution, and land degradation. This can have a negative impact on the environment, as well as on the health and well-being of local communities.
• Health hazards: Miners are exposed to hazardous working conditions, including toxic chemicals, dust, and noise pollution. This can lead to respiratory problems, hearing loss, and other health issues.
• Conflict: Mining activities can often result in conflict between different groups over access to resources, land rights, and control over the benefits of mining.
• Economic dependence: Many West African countries heavily rely on the revenue generated by mining. This can result in economic dependence on a single resource, leaving the country vulnerable to fluctuations in commodity prices and other economic shocks.

Détails de la réponse

None

Détails de la réponse

None

Détails de la réponse

None