JAMB UTME - Geography - 2024

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The term over-population is best defined as the situation where the population exceeds available resources. This means that the number of people in an area is greater than the resources available to sustain them, such as food, water, shelter, and health care. It can lead to various problems including poverty, environmental degradation, and a strain on infrastructure. Over-population occurs when the existing resources cannot meet the needs of the people, resulting in hardship and reduced quality of life.

In contrast, having a birth rate equal to the death rate implies a stable population over time, not necessarily over-population. Increasing birth rate and decreasing infant mortality can contribute to population growth, but they do not solely define over-population. Finally, high population density refers to a large number of people living in a small area, which could lead to over-population if resources are insufficient, but high density alone does not equate to over-population.

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Wind action is more predominant in arid regions due to the combination of loose surface materials and the absence of vegetation cover. In these regions, there is little moisture to bind soil particles together, making them easily detachable and transportable by wind. Without vegetation to stabilize the soil and buffer wind, these loose particles are swept away, leading to significant wind erosion.

Other reasons, such as insufficient drainage or strong winds, also play a role; however, the **primary** factors are the loose surface materials and lack of vegetation, allowing wind to act with greater intensity. In contrast, humid regions have ample vegetation and soil moisture, which significantly reduce the wind's ability to erode and transport surface material.

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Let's understand the term **headward erosion**. **Headward erosion** refers to the process where a river or stream erodes its source region, causing the stream's origin to move backward away from the direction of water flow. This process can have several impacts and can lead to the formation of certain landforms.

Among the options provided, **headward erosion** is most commonly associated with the formation of **river capture**. When **headward erosion** continues over time, it can cause one river to extend its course and intersect with a neighboring river, capturing its flow. This event is known as **river capture** or **stream piracy**. Essentially, the rapid erosion at the river's source enables it to cut through the drainage divide and capture the headwaters of another river.

Let's briefly see why the other options are less relevant to **headward erosion**:

• **Potholes** are typically formed on the riverbed as a result of mechanical weathering and the swirling movement of water and debris, rather than headward erosion.
• **Oxbow lakes** form when a meander from a river is cut off, creating a free-standing body of water, which is more a result of lateral erosion rather than headward erosion.
• **Alluvial cones** or **alluvial fans** form where a river or stream spreads out sediment as it exits a mountainous area onto a flatter plain. This is not directly caused by **headward erosion**, but rather sediment deposition.

Therefore, the process of **headward erosion** most directly leads to the formation of **river capture**.

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Nigeria, a country located in West Africa, is situated between the longitudes of 3°E and 15°E. Longitude lines are imaginary vertical lines that run across the Earth's surface from the North Pole to the South Pole. These lines help in determining the east-west position of a particular location on earth. By being positioned between 3°E and 15°E, Nigeria stretches from slightly east of the Prime Meridian, which is 0°, to 15° eastward. This geographical positioning affects several aspects like climate and time zone, making it an important detail in understanding the country's location globally.

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The ocean that connects Europe and America is the Atlantic Ocean.

Here's a simple explanation: The Atlantic Ocean is a massive body of water that lies between the continents of Europe and Africa to the east and the Americas to the west. This ocean is one of the world's five major oceans and is the second largest after the Pacific Ocean. Historically, the Atlantic Ocean has been significantly important as a route for ships traveling between Europe and the Americas, playing a crucial role in exploration, commerce, and cultural exchanges.

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The longest river in Africa is the Nile River. The Nile River is renowned for its extraordinary length, stretching approximately 6,650 kilometers (about 4,130 miles). This majestic river traverses several countries in northeastern Africa, including Uganda, Sudan, and primarily Egypt. Its extensive reach makes it the longest river not only in Africa but also in the world, although there is some debate with the Amazon River.

The Nile plays a crucial role in the cultures and economies of the nations it flows through. In ancient Egypt, for instance, it was vital for agriculture, enabling civilizations to thrive by providing a reliable source of water and fertile land for farming. Today, the Nile continues to be a lifeline for millions of people, supporting agriculture, transport, and providing drinking water.

In contrast, the other rivers mentioned, such as the Zambezi, Senegal, and Congo, though significant in their own right, are shorter and do not match the extraordinary length of the Nile River.

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Rural-urban migration refers to the movement of people from rural areas to urban areas in search of better opportunities and living conditions. One of the main effects of this kind of migration is rural depopulation.

Here's why:

• Rural Depopulation: When significant numbers of individuals leave the rural areas for urban centers, the population in these rural areas declines. This is because more people are exiting than entering these areas. As a result, the overall population density decreases.


• Rural Unemployment: Paradoxically, rural unemployment might decrease rather than increase. This is because those who migrate are often people who were already unemployed or underemployed and looking for better job opportunities. When they leave, the unemployment rate in the rural area may stabilize or even decrease because the remaining population might have more employment opportunities.


• Rural Congestion: Is not an effect of rural-urban migration. In fact, with fewer people, congestion in rural areas typically diminishes.


• Urban Depopulation: When people migrate from rural areas to urban areas, the urban areas' population increases while the rural areas' population decreases. Hence, urban depopulation is not applicable in this context.

In summary, rural depopulation is one of the primary effects of rural-urban migration as it results in a decrease in the population of the rural areas being vacated.

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Rocks that are formed from the cooling and solidification of molten magma are called igneous rocks.

To put it simply, when rocks melt deep beneath the Earth's surface because of the high temperatures, they turn into a liquid called magma. This magma can sometimes rise to the surface in the form of lava. Once either the magma or lava cools down and becomes solid, it forms a new type of rock known as igneous rock.

These rocks can be formed inside the Earth when the magma cools slowly, creating large crystals, or on the Earth's surface, when the lava cools quickly, often resulting in smaller crystals. The word "igneous" comes from a Latin word meaning "fire," which appropriately describes how these rocks form from the hot, molten magma.

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A geyser is best described as a fountain of superheated steam. This natural phenomenon occurs when water that is trapped beneath the Earth's surface is heated by geothermal activity, such as volcanic activity, deep underground. As the water is heated, it turns into steam and builds up pressure. This pressure eventually forces the steam and hot water to be expelled violently from the ground in a dramatic outburst, creating a fountain-like effect.

Let's break this down a bit more:

• A geyser consists of a network of underground channels filled with water. The heat from molten rock (magma) heats the water in these channels.
• As the water heats, it expands and turns into steam. However, due to the depths, the water above creates pressure that allows the water below to reach temperatures above the normal boiling point.
• When this pressure is released, often when bubbles of steam rise to a narrow section of the channel nearest the surface, the superheated water violently boils, pushes through the surface, and escapes as steam and hot water – hence, a fountain of superheated steam.

This distinct eruption is what characterizes a geyser and differentiates it from other geothermal features like hot springs or thermal pools, which do not erupt but simply release heat gradually into the water.

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The temperatures of adjacent coastlands are reduced when on-shore winds blow over cold currents primarily because the cold currents influence the temperature of the prevailing winds.

Here's how it works in simple terms:

When winds blow over the ocean surface, they pick up characteristics of the water beneath them. If these winds travel over a cold ocean current, the air they carry becomes cooler. As this cooler air moves onto the coastlands, it brings down the temperature of those areas. This is why coastlands experience reduced temperatures when on-shore winds carry the chill from cold ocean currents.

So, the key factor here is the cooling effect of the cold water, which cools the air above it, consequently lowering the temperature of the coastal regions the wind blows onto.

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In terms of the largest timber producers in Africa, it is important to understand which nation has significant timber resources and an established forestry industry. Zaire, known today as the Democratic Republic of Congo (DRC), is recognized as the largest timber producer in Africa.

The Democratic Republic of Congo has extensive forest coverage, including parts of the Congo Basin, which is the second-largest rainforest in the world after the Amazon. This vast expanse of forestland provides an abundance of timber resources. The country's forestry industry has developed around this natural resource, contributing significantly to its economy.

Other countries like Ghana and Nigeria also have substantial forests and timber industries, but they do not match the scale of Zaire. Malawi, on the other hand, is less known for timber production compared to these countries.

In summary, considering its massive forest expanse and established timber industry, Zaire (the Democratic Republic of Congo) stands out as Africa's largest timber producer.

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The climatic type found on the western margins of continents between latitudes 30° and 40° North and South of the Equator is the Mediterranean climate.

The Mediterranean climate is characterized by its unique seasonal weather pattern:

• Hot, dry summers: During the summer months, these regions usually experience clear skies, ample sunshine, and little to no rainfall. The temperatures are generally high due to the influence of the subtropical high-pressure systems.
• Mild, wet winters: In the winter months, these areas receive moderate rainfall, often brought by westerly winds and cyclonic storms, while temperatures remain relatively mild and comfortable.

This type of climate is well-known for supporting specific kinds of ecosystems and is suitable for growing certain crops, such as olives, grapes, and wheat. Typical regions with a Mediterranean climate include the coastal areas of the Mediterranean Sea, parts of California in the United States, central Chile, the southern tip of South Africa, and southwestern Australia.

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Coal is associated with organically-formed sedimentary rocks.

To understand why coal is associated with this type of rock, let's break it down:

1. **Sedimentary Rocks:** These rocks are formed from particles or sediments that accumulate and consolidate over time. Sedimentary rocks can be broken down further into different types based on their origins.

2. **Organically-formed Sedimentary Rocks:** This subgroup specifically forms from the accumulation of organic material, including plants and animals. Over millions of years, the remains of plants (especially those from swampy or wetland areas) accumulate in layers. As more and more layers build up, the pressure and heat from above cause these plant materials to transform into coal. Thus, coal is formed over long geological periods, through the compression of organic plant material.

This process differentiates organically-formed sedimentary rocks from mechanically-formed sedimentary rocks, which result from the mechanical process of weathering and erosion of existing rocks, and from igneous rocks like plutonic, which form from the solidification of magma, and crystalline rocks, which are typically associated with metamorphic processes. Thus, **coal is uniquely tied to organically-formed sedimentary rocks because of its plant-based origin**.

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Mechanical weathering is the process of breaking down rocks into smaller pieces without changing their chemical composition. There are several causes of mechanical weathering, but not all processes that affect rocks are related to mechanical weathering.

The options listed include:

Temperature changes: This is a cause of mechanical weathering. When rocks are exposed to fluctuating temperatures, they expand when it's hot and contract when it's cold. Over time, these repeated expansions and contractions can cause the rocks to crack and break apart.

Frost action: Also known as freeze-thaw weathering, this is another form of mechanical weathering. Water can seep into cracks in the rocks, and as temperatures drop, the water freezes and expands. This expansion exerts pressure on the rock, gradually breaking it apart.

Alternate wetting and drying: This causes mechanical weathering by changing the volume of clay minerals found in some rocks. When these rocks get wet, the clay swells, and when dry, it contracts. This constant expansion and contraction lead to mechanical breakdown.

Rain action: This is not primarily a cause of mechanical weathering. While rain can contribute to weathering processes, such as chemical weathering where it reacts with minerals in rocks to form new compounds, its primary role in mechanical weathering is minimal compared to other factors.

Therefore, among the options provided, rain action is the one that is not a direct cause of mechanical weathering.

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On June 21st, when the sun is overhead at the Tropic of Cancer, places in the Northern Hemisphere experience a phenomenon often referred to as the **Summer Solstice**. This day marks the point when the Northern Hemisphere is tilted closest to the Sun. As a result, it receives the most direct sunlight compared to any other day of the year.

During this time, the day is significantly longer than the night. This is because the Sun travels a longer path through the sky, remaining visible for a larger portion of the 24-hour day. Therefore, areas in the Northern Hemisphere experience a **longer day and shorter night**.

This occurrence is most noticeable the further north you go, with some regions near the Arctic Circle experiencing the phenomenon known as the "Midnight Sun," where the sun is visible at midnight.

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Population density refers to the number of people living per unit of area, typically measured in people per square kilometer. In Nigeria, several factors influence population density, including natural, economic, and social factors.

Thick forest vegetation can influence population density by limiting the availability of land for habitation and agricultural activities. Areas with dense forests are usually less populated because they are harder to clear for settlements and farming. Additionally, thick forests may not have sufficient infrastructure, making them less attractive for people to live in.

Similarly, tsetse fly infestation can significantly influence population density. The tsetse fly transmits sleeping sickness, which can be a health hazard for humans and animals. Areas infested with tsetse flies might have lower population densities because people avoid settling in regions where their health and that of their livestock are at risk.

Fertile agricultural land attracts people because it supports farming activities, which is a primary livelihood for many people in Nigeria. As a result, such areas often have higher population densities due to the economic opportunities they provide.

The factor that least influences population density among the given options is mining. While mining can attract workers to specific areas, its influence is usually limited to certain regions where mineral resources are available. Since mining is typically localized and not widespread, its impact on overall population density is generally lower compared to factors like agriculture or disease. Additionally, mining areas might not have sustainable living conditions to attract large populations permanently.

In summary, while all these factors can influence population density, mining has the least impact compared to the other options because it affects fewer regions and often does not provide long-term settlement opportunities.

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The term fossil fuel refers to energy sources that come from the remains of ancient plants and animals, buried and subjected to heat and pressure over millions of years. These fuels are primarily composed of carbon and include materials like coal, oil, and natural gas.

Among the options given:

• Gneiss is a type of metamorphic rock formed from other rocks like granite or sedimentary rock through heat and pressure. It is not a fossil fuel.
• Granite is an igneous rock that forms from the cooling and solidification of magma beneath the Earth’s surface. It is not a fossil fuel.
• Lignite is a type of coal, which is a fossil fuel. It is often referred to as brown coal and is used primarily as a fuel for steam-electric power generation.
• Mica is a group of minerals that can split into thin, tough sheets. It is not a fossil fuel.

Therefore, the correct answer is Lignite because it belongs to the category of fossil fuels. Lignite is formed from the remains of plants that lived millions of years ago, which makes it a source of stored energy that can be burned for heat and power.

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The major industrial zones of Nigeria owe their origin mainly to the presence of cash crops. This is because, historically, Nigeria's economy largely depended on agriculture, and the availability of these cash crops provided a foundation for establishing industries. For example, regions where cash crops such as cocoa, palm oil, rubber, and groundnuts were abundantly grown became focal points for industries.


These crops were in high demand both locally and internationally, encouraging the establishment of processing industries to add value before export. This led to the development of infrastructure and contributed to the economic growth of these regions.


Thus, the presence of cash crops has played a significant role in shaping the industrial landscape of Nigeria by attracting investments, creating jobs, and fostering economic development in the respective regions.

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Hong Kong, Java, and Manhattan all share the feature of having a **high population density**. These regions are known for their concentrated population in relatively small areas. Here is a simple explanation for each:

• Hong Kong: As a major financial and cultural center, Hong Kong is known for its skyscrapers and bustling city life, housing a large number of people in a compact space.


• Java: This Indonesian island is one of the most densely populated places in the world, being the political, economic, and cultural hub of Indonesia.


• Manhattan: In New York City, Manhattan is famous for its urban density, with many people living and working in high-rise buildings within a small area, contributing to its status as a significant commercial and cultural center.

In summary, the common feature among these locations is their **high population density**, where large numbers of people reside and engage in various activities within limited geographic spaces.

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The Economic Community of West African States (ECOWAS) is a regional political and economic union of countries located in West Africa. Its objective is to promote economic integration across the region. The official member states of ECOWAS include countries in West Africa.

Among the options provided:

• Cote d'Ivoire is a member of ECOWAS. It is located in West Africa and actively participates in the community’s activities.
• Burkina Faso is also a member of ECOWAS. Like Cote d'Ivoire, it is found in West Africa and is part of the union.
• Senegal is another member state of ECOWAS, contributing to the regional integration efforts.

Cameroun, however, is not a member of ECOWAS. While it is geographically close to West Africa, it is primarily considered part of Central Africa, and it is a member of the Central African community organization instead.

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An example of an organically formed sedimentary rock is coal.

Coal is formed from the remains of dead plants that accumulated in ancient swamps and wetlands. Over millions of years, these plant materials were buried under layers of sediment. As more layers built up on top, the increased pressure and heat transformed the plant remains into coal. The process involved is known as biochemical sedimentation, where organic materials are compacted and altered to form rock.

This is in contrast to the other options:

• Granite is an igneous rock, not sedimentary, formed from cooled magma or lava.
• Rock salt is a chemical sedimentary rock formed when water evaporates, leaving behind salt crystals.
• Sandstone is a clastic sedimentary rock formed from compacted sand particles.

To summarize, coal is the organically formed sedimentary rock among these options because it originates from ancient plant material that has undergone compaction and chemical transformation over time.

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One characteristic that distinguishes urban settlements from rural settlements is that urban settlements are areas of secondary and tertiary activities.

Let's break this down:

• Urban Settlements: These are typically characterized by higher population density and more developed infrastructure. The economic activities here are primarily focused on secondary activities, such as manufacturing and industry, and tertiary activities, such as services like banking, education, healthcare, and retail. These activities are associated with more advanced stages of economic development and are common in cities and larger towns.


• Rural Settlements: On the other hand, rural areas are often associated with primary activities, such as agriculture, fishing, forestry, and mining. These activities involve direct extraction or harvesting of natural resources and are more common in less densely populated areas like villages or countryside.

To summarize, the primary distinction is that urban settlements focus on secondary and tertiary activities, providing goods and services, ultimately making them different in function and character from rural settlements, which focus more on primary activities.

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The bush fallowing system in West Africa is not very economical in the use of land. Bush fallowing involves leaving land fallow for several years to regain its fertility, which can lead to inefficient use of land.

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To determine which of the listed items is not an element of climate, we need to understand what elements constitute climate. **Climate** refers to the average weather conditions of a place over a long period, typically 30 years or more. The primary elements that define climate include **temperature**, **precipitation**, **humidity**, **wind**, and **air pressure**. Let's go through the choices given:

Precipitation: This is an important element of climate as it refers to any form of moisture that falls from the atmosphere to the earth's surface, such as rain, snow, or sleet.

Air pressure: This is a crucial element of climate because it influences wind patterns and weather systems such as cyclones and anticyclones.

Altitude: This is not an element of climate; rather, it is a geographic factor that influences climate. As you go higher in altitude, temperatures typically decrease, which can affect the climate of a region, but altitude itself is not a climatic element.

Temperature: This is a fundamental element of climate, affecting the average warmth or coldness of a place over time.

Therefore, **altitude** is not an element of climate, but a factor that can influence the other elements like **temperature** and **precipitation**.

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Mercury and Venus are the two planets that lie between the Sun and Earth.

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The development of hydro-electric power in Nigeria is least affected by the availability of suitable sites for dams. While suitable sites are necessary for building dams, other factors such as a regular supply of water and high mountains are more critical for hydro-electric power development.

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The **Horn of Africa** is a prominent peninsula in East Africa that juts into the Arabian Sea. It consists primarily of four countries: **Ethiopia**, **Eritrea**, **Somalia**, and **Djibouti**. From the options provided, only **Djibouti** is located within the Horn of Africa. This makes Djibouti geographically significant in terms of its positioning in this specific region.

For further understanding, here is a brief description of the other countries mentioned:

• Kenya: Although located in East Africa, it is situated below Ethiopia and does not form part of the Horn of Africa.
• Chad: This country is located in Central Africa and is far away from the Horn of Africa.
• Swaziland (now called Eswatini): This is a landlocked country in Southern Africa, nowhere near the Horn of Africa.

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The major source of power for most terrestrial ecosystems is solar energy.

Let me explain why:

Solar energy is the energy that comes from the sun. It is critical for life on Earth as it powers the process of photosynthesis, which is used by plants, algae, and some bacteria to convert light energy into chemical energy. During photosynthesis, these organisms take in carbon dioxide from the air and water from the soil, and with the help of sunlight, they produce glucose and oxygen. This process provides the necessary energy and organic material to support life.

Here is why it is important:

• Primary Producers: Solar energy fuels the primary producers (mainly plants) that form the base of the food chain. They use sunlight to create food that herbivores eat, and these herbivores are then consumed by carnivores. Without the energy provided by the sun, this foundational level of the food web would not exist, and all life forms that depend on plants, either directly or indirectly, would not survive.
• Energy Transfer: The energy captured by plants is transferred through various trophic levels as different organisms consume one another. Each level receives energy that originated from the sun, making solar energy the primary driving force of energy flow in ecosystems.
• Climate Regulation: Sunlight helps regulate Earth's climate and atmospheric conditions, influencing temperature and weather patterns. These conditions are necessary for the survival of various ecosystems and their inhabitants.

In comparison, other energy sources like geothermal energy, nuclear power, and hydroelectric power play relatively minor roles in terrestrial ecosystems. These energies are not as directly involved in powering the basic life-sustaining processes as solar energy is. Therefore, it is clear that solar energy is the predominant power source for life on land.

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The equatorial diameter of the earth is approximately 6,760 km. This is the distance from the equator to the equator, passing through the center of the earth.

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The **most common mode of transportation in Africa** is **road transportation**. This includes vehicles like cars, buses, and motorcycles that travel on roads and highways. Road transportation is widespread because it is **versatile** and can reach many rural and urban areas that are not accessible by other means of transportation. Roads are often less expensive to build and maintain compared to infrastructure needed for other modes such as railways or airports.

Despite the challenges such as limited road networks and varying road conditions in some regions, **road transportation remains the backbone** of both passenger and freight transport due to its **flexibility** and **accessibility**. In many African countries, it is the most relied upon form of transport connecting people to markets, healthcare facilities, schools, and places of employment.

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Quartzite, schist, and marble are all examples of metamorphic rocks.

Here's why:

• Metamorphic Rocks: These are rocks that have undergone a transformation due to intense heat and pressure. This process, called metamorphism, alters their original form or mineral composition without melting them.
• Quartzite: This forms from sandstone, a sedimentary rock, that has been exposed to heat and pressure, resulting in a very hard, durable rock.
• Schist: This rock is typically formed from shale, another sedimentary rock, or sometimes from basalt, an igneous rock. It has a shiny appearance due to the presence of mica minerals.
• Marble: This is formed from limestone, a sedimentary rock that undergoes recrystallization under high heat and pressure, resulting in a rock that is often used in sculpture and architecture.

Sedimentary Rocks are formed from the accumulation of sediments, while Igneous Rocks are formed from the cooling and solidification of magma or lava. Volcanic rocks are a subset of igneous rocks that specifically form from lava at the earth's surface. Thus, quartzite, schist, and marble do not fall under these categories.

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The Biu Plateau has an average height of over 100 meters above sea level. The Biu Plateau is a region of high ground in northeastern Nigeria

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A settlement developed at the meeting point of roads is known as a nodal town.

Let's break this down in a simple way:

• A nodal town is a type of settlement that forms at a junction or intersection where different roads, railways, or other routes meet. It acts like a central point or a node, where transportation and communication lines converge.
• These towns are important because they serve as transportation hubs, making it easy for people and goods to travel in various directions.
• The meeting of different routes encourages trade, commerce, and interactions between different regions, leading to the town’s growth and development.

In contrast, a port town develops around a harbor, a confluence town forms where rivers meet, and a gap town evolves in mountain pass regions. Thus, a town at the meeting point of roads is distinctly identified as a nodal town.

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The mountains formed as a result of compressional forces in the Earth's crust are known as fold mountains. Fold mountains are created when two tectonic plates collide, and the compressional forces involved cause the layers of the Earth's crust to crumple and fold.

Imagine it like pushing two pieces of paper together from opposite ends; they begin to crumple and form folds. Similarly, when large sections of the Earth's crust are subjected to immense pressures from the sides, they buckle and bend into wave-like structures called folds. These folds then rise over time to form fold mountains.

Some of the most well-known mountain ranges in the world, like the Himalayas, the Alps, and the Rockies, are examples of fold mountains.

In summary, fold mountains are formed by the compression and folding of the Earth's crust, making them a direct result of tectonic forces that push the land upwards to form mountains.

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To determine which option is not a proof of the Earth's spherical shape, let's examine each one:

Twilight and Dawn: Twilight and dawn occur when the Earth rotates, and the sun is below the horizon. The gradual increase or decrease in light during these times is due to the atmosphere bending or scattering sunlight. While this phenomenon is observed worldwide, it by itself doesn't directly indicate a spherical Earth. Instead, it emphasizes the Earth's rotation, which is consistent with a spherical shape.

Lunar Eclipse: During a lunar eclipse, when the Earth is directly between the sun and the moon, the Earth casts a shadow on the moon. This shadow is observed as a circular shape, which provides direct evidence that the Earth is spherical.

Aerial Photograph: Aerial photographs, when taken from a sufficient altitude, can show the curvature of the Earth. Photographs taken from high altitudes give visual evidence of the Earth's curved surface, supporting the spherical shape.

Sunrise and Sunset: The occurrence of sunrise and sunset happens due to the Earth's rotation on its axis. As the Earth rotates, different parts of the world experience sunlight and darkness. This rotation is consistent with the global experience of a spherical planet.

Conclusion: While all the listed phenomena have some connection to the Earth's rotation and shape, **twilight and dawn** do not directly serve as a proof of the Earth's spherical shape. They are more indicative of the rotational aspect and atmospheric effects rather than the shape itself.

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The geographical region of Nigeria described in the question is the North-Central Highlands. This area covers about one-fifth of the country and is characterized by a generally flat surface with granitic hills, known as inselbergs, scattered throughout the landscape. These hills are composed of hard rock formations that have resisted erosion, thereby standing out from the flatter surroundings.

This region is situated in the north-central part of Nigeria and is significant for its geological features and agricultural potential. The flat terrain provides an expansive area suitable for farming, while the inselbergs add to the region's natural beauty and sometimes serve as landmarks. The North-Central Highlands are an important and distinct geographical region within Nigeria due to these unique characteristics.

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The decline in the importance of rail transport in Africa can be best explained by the high competition from road transport. Here's why:

Accessibility and Flexibility: Road transport is generally more accessible and flexible compared to railways. Roads are available in most areas of Africa, including rural regions, allowing goods and passengers to reach their destinations directly without requiring transfer between modes of transport.

Cost-Effectiveness: In many cases, road transport can be more cost-effective because it eliminates the need for transferring goods at several points. The initial investment in road infrastructure and vehicles can also be less than maintaining or upgrading railway networks.

Adaptability to Infrastructure Limitations: Many railways in Africa suffer from outdated infrastructure, which can hinder their efficiency and reliability. On the other hand, road transport can easily adapt to newer roads and infrastructures as they are developed.

Length of Transport Routes: Although Africa is a vast continent, many trade routes within countries or regions are more economically feasible with road transport, especially for short to medium distances.

Overall, while other factors such as the low volume of goods and potential retrenchment threats exist, the dominance and rapid improvement in the road transport sector particularly highlight why rail transport has seen a decline in relevance. The flexibility and economic viability of road transport often make it a more attractive choice for businesses and individuals alike.

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The part of the earth's crust that is covered by oceans and seas is called the hydrosphere.

Let's break it down logically:

• The hydrosphere specifically refers to all of the water found on, under, and over the surface of the Earth, including oceans, seas, rivers, lakes, and even water in the atmosphere.
• It covers about 71% of the Earth's surface, making it a significant and distinctive part of the planet.
• The stratosphere and the ionosphere are layers of the Earth's atmosphere, not related to water or Earth's crust coverage.
• The biosphere refers to all regions of the Earth occupied by living organisms. While it includes oceans and seas, it is not specific to just water coverage.

Therefore, the term that correctly describes the part of the Earth's crust covered by water bodies like oceans and seas is the hydrosphere.

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The ancient Greeks were pioneers in observing and classifying the Earth's climate zones. They recognized three primary climatic belts based on their understanding of the Earth's environment. These belts were:

• Torrid Zone: This zone is the hottest part of the Earth, located near the equator. The Greeks believed it to be extremely warm because it lies where the sunlight strikes the Earth most directly. Today, we know this region as the tropical zone.
• Temperate Zone: This area lies between the torrid and frigid zones. It experiences more moderate temperatures. The Greeks saw this as a **habitable** zone, with a climate suitable for a majority of human living. It corresponds to the mid-latitudes in modern geography.
• Frigid Zone: This is the coldest area, positioned around the poles. The Greeks considered it extremely cold and largely uninhabitable due to its distance from the equator and the angle at which sunlight reaches these regions. Today, this relates to the polar regions.

Thus, the Greeks recognized these **three climatic belts**: Torrid, Temperate, and Frigid. This classification was an early attempt to systematically understand the Earth's climatic patterns using observable natural phenomena, such as sunlight and temperature differences.

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A mercury barometer is used for measuring atmospheric pressure.

Here's a simple explanation:

A barometer is an instrument designed to measure the pressure exerted by the atmosphere. The atmosphere exerts pressure because of the mass of air above the Earth, and this pressure changes as you move up and down in altitude or due to weather systems.

A mercury barometer consists of a long glass tube closed at one end and filled with mercury. The open end of the tube is placed in a bowl of mercury, called a reservoir. The pressure from the air pushing down on the mercury in the bowl forces the mercury up the tube. When the atmospheric pressure is high, the mercury in the tube rises, and when the atmospheric pressure is low, the mercury level falls.

Thus, by measuring the height of the mercury column in the tube, we can determine the atmospheric pressure. In summary, a mercury barometer provides a way to directly observe changes in the atmospheric pressure.