Important Questions Test: Major Domains Of The Earth - UPSC MCQ

Antarctica is not an ocean; it is a continent located at the southernmost part of the Earth. Here are some key points about Antarctica:

• Geography: Surrounded by the Southern Ocean, Antarctica is the fifth-largest continent.
• Climate: It is the coldest, windiest, and driest continent, with ice covering about 98% of its land.
• Wildlife: Home to unique species like penguins, seals, and various seabirds, it supports rich marine ecosystems in surrounding waters.
• Research: The continent is crucial for scientific research, particularly in climate change and glaciology.

In contrast, the Indian, Pacific, and Atlantic are all large bodies of water known as oceans. Each plays a vital role in Earth's climate, marine biodiversity, and global trade.

The Arctic Circle passes through Europe. This continent is situated to the west of Asia and is bordered by water on three sides. Here are some key points:

• Europe is smaller than Asia and forms part of the larger landmass known as Eurasia.
• The Arctic Circle is an important circle of latitude that intersects Europe.
• Europe's geographical limits are defined by various bodies of water.

For a better understanding, refer to a world map to see the locations of Europe and the Arctic Circle.

Everest is known as the highest mountain peak on Earth, reaching an impressive height of 8,848.86 metres (29,031.7 feet) above sea level. Here are some key points about Everest:

• Located in the Himalayas, on the border between Nepal and the Tibet Autonomous Region of China.
• First successfully climbed on May 29, 1953, by Sir Edmund Hillary and Tenzing Norgay.
• Attracts many climbers each year, ranging from experienced mountaineers to novices.
• Severe conditions, including extreme cold and high altitude, present significant challenges.

Other notable peaks include:

• K2: The second highest mountain, known for its difficulty.
• Kanchenjunga: The third highest peak, located on the India-Nepal border.
• Aravalli range: An ancient mountain range in India, much lower than Everest.

The two continents that lie entirely in the southern hemisphere are:

• Australia - The smallest continent, known for its unique wildlife and landscapes.
• Antarctica - A vast, icy landmass primarily covered in ice, known for its extreme climate.

The atmosphere consists of various layers, each with distinct characteristics. The main layers include:

• Troposphere: This is the lowest layer where weather occurs. It contains most of the atmosphere's mass and extends from the Earth's surface up to about 8 to 15 kilometres.
• Stratosphere: Located above the troposphere, this layer contains the ozone layer, which protects us from harmful ultraviolet radiation. It extends from around 15 to 50 kilometres above the Earth.
• Mesosphere: Above the stratosphere, this layer is where meteoroids burn up upon entering the atmosphere. It extends from about 50 to 85 kilometres.
• Thermosphere: This layer is known for its high temperatures and is where the auroras occur. It extends from about 85 to 600 kilometres above the Earth.

In contrast, the hydrosphere refers to all the water on Earth, including oceans, rivers, and lakes. It is not classified as a layer of the atmosphere.

Australia is the smallest continent in the world.

Here are some key points about Australia:

• It is located in the Southern Hemisphere.
• Australia is often referred to as an island continent due to its landmass being surrounded by water.
• It covers an area of approximately 7.7 million square kilometres.
• Australia is known for its diverse ecosystems, including deserts, rainforests, and coral reefs.

In comparison, other continents are larger:

• Africa is the second-largest continent.
• North America and South America are also significantly larger than Australia.

Thus, when considering the size of continents, Australia holds the title of the smallest.

The hydrosphere consists of all the water found on Earth, which includes various components. Here are the main elements:

• Rivers: Flowing bodies of freshwater that drain into larger bodies like lakes or oceans.
• Ice sheets: Large, thick masses of ice covering significant land areas, found mainly in polar regions.
• Oceans: Vast bodies of saltwater that cover about 71% of the Earth's surface.

However, rocks are not part of the hydrosphere. They are part of the lithosphere, which includes the Earth's crust and upper mantle.

The Atlantic Ocean is known for its distinctive 'S' shape and is home to some of the world's busiest ports. Here are key features:

• Geography: Its unique shape significantly influences global trade routes.
• Commerce: Major ports include New York, Rotterdam, and Liverpool, facilitating extensive shipping activities.
• Cultural Significance: The Atlantic has historically been a vital link between continents, fostering cultural exchange.

In comparison to other oceans, the Atlantic stands out for its role in international commerce and its geographic characteristics.

A large part of Africa lies in the

• Africa is situated in both the Northern and Southern Hemispheres.
• Approximately 60% of the continent is located in the Northern Hemisphere.
• The equator runs through the middle of Africa, dividing it into these two hemispheres.
• Countries such as Egypt and Libya are in the Northern Hemisphere, while nations like South Africa and Angola are in the Southern Hemisphere.

This geographical division is essential for understanding climate patterns, ecosystems, and biodiversity across the continent.

Life is primarily found on Earth, where the conditions support various forms of organisms. Here are some key points regarding life on Earth:

• Water: Earth has abundant liquid water, essential for all known life forms.
• Atmosphere: The atmosphere contains oxygen and other gases that are crucial for respiration.
• Climate: Diverse climates support different ecosystems, from rainforests to deserts.
• Biodiversity: Earth is home to millions of species, contributing to a rich variety of life.

While other planets like Mars have shown potential signs of past water and possible microbial life, they currently do not support life as we know it. Venus and Mercury have extreme conditions that are inhospitable for life.

The continent of North America is connected to South America by a narrow land bridge known as an isthmus. This geographical feature plays a crucial role in the formation of the Americas, allowing for the movement of both wildlife and human populations between the two continents.

• An isthmus is a narrow strip of land that links two larger landmasses.
• The most notable isthmus connecting North and South America is the Isthmus of Panama.
• This region is significant for trade and biodiversity.
• It serves as a natural barrier and a point of interaction for various species.

Understanding the role of the isthmus is essential for appreciating how the two continents have evolved both ecologically and culturally.

North America is situated primarily in the:

• Northern Hemisphere
• Western Hemisphere

Here are some key points about its location:

• It extends from the Arctic Circle in the north to the tropics in the south.
• It is bordered by the Atlantic Ocean to the east and the Pacific Ocean to the west.
• Countries like the United States, Canada, and Mexico are part of this continent.

In summary, North America lies in the Northern and Western hemispheres.

Africa is the only continent that lies on both sides of the equator. Here are some key points about Africa's position:

• Africa is located in both the Northern and Southern Hemispheres.
• The equator runs approximately through the centre of the continent.
• This geographical position contributes to Africa's diverse climate and ecosystems.
• Regions on the equator generally experience tropical weather patterns.

Other continents mentioned do not straddle the equator, making Africa unique in this aspect.

Indian Ocean is the ocean named after a country. Its shape is often described as triangular, as it is bordered by several nations and extends between Africa, Asia, Australia, and the Indian subcontinent.

• The Indian Ocean is the third largest ocean in the world.
• It covers an area of approximately 70.56 million square kilometres.
• This ocean is crucial for global trade and shipping routes.
• It is known for its diverse marine life and unique ecosystems.

The Nile is the longest river in Africa and is renowned for its significant role in the history and culture of the continent.

• It flows for approximately 6,650 kilometres, making it one of the longest rivers in the world.
• The Nile traverses several countries, including Uganda, Sudan, and Egypt.
• It has two main tributaries: the White Nile and the Blue Nile.
• The river has been crucial for agriculture, providing water to the arid regions surrounding it.
• Historically, it was vital for the development of ancient Egyptian civilization.

In contrast, the other rivers mentioned, such as the Yamuna, Ganga, and Kaveri, are significant but do not match the Nile's length.