STD 5 Th Evs

Explanation
The earth is surrounded by the atmosphere, which is a layer of gases that envelops the planet. The atmosphere plays a crucial role in supporting life on earth by providing the air we breathe, regulating temperature, and protecting us from harmful radiation. It is composed of various gases such as nitrogen, oxygen, carbon dioxide, and trace amounts of other gases. The atmosphere is divided into different layers, each with its own characteristics and functions. Overall, the atmosphere is essential for maintaining the conditions necessary for life to exist on earth.

Explanation
The Sun is the cause of many natural processes such as the Earth's climate, weather patterns, and the generation of heat and light. It provides the energy needed for photosynthesis in plants, which is the basis of the food chain. The Sun's gravitational pull also influences the tides on Earth. Additionally, the Sun's radiation drives the water cycle, causing evaporation and precipitation. Overall, the Sun plays a crucial role in sustaining life on Earth and driving various natural phenomena.

Explanation
The earth's crust is hard because it is made up of solid rock and minerals that form a rigid outer layer. This layer provides stability and support to the earth's surface, preventing it from easily breaking or deforming. The hardness of the earth's crust is essential for the formation and maintenance of landforms such as mountains, plateaus, and valleys. Additionally, the hardness of the crust allows for the movement of tectonic plates, which is responsible for earthquakes and the creation of new land.

Explanation
Kangaroos are found only in Australia. This is because kangaroos are native to Australia and are considered an iconic symbol of the country. They have adapted to the unique Australian environment over millions of years and are well-suited to its arid and grassy landscapes. Kangaroos are not found in the USA or Africa, making Australia the correct answer.

Explanation
Ozone is the correct answer because it is a gas found in the stratosphere that is responsible for absorbing harmful ultraviolet rays from the sun. Ozone acts as a protective layer for the Earth's surface, preventing excessive UV radiation from reaching the ground and causing damage to living organisms. Nitrogen and helium are not known for their ability to absorb UV rays, making them incorrect options.

Explanation
The statement suggests that there are certain regions that are consistently covered with ice, while others have a hot climate. This implies that there are indeed regions on Earth that experience extreme cold and regions that experience extreme heat, supporting the statement that the answer is true.

Explanation
The envelope of air around the earth is actually called the atmosphere, not the hydrosphere. The hydrosphere refers to all the water on or near the earth's surface, including oceans, lakes, rivers, and groundwater. Therefore, the statement is false.

Explanation
Water on the earth evaporates continuously due to the heat of the sun. This is because the sun's energy causes the water molecules to gain enough energy to break free from the liquid state and become water vapor in the atmosphere. This process is known as evaporation and it is an important part of the water cycle, where water continuously moves between the earth's surface and the atmosphere.

Explanation
The statement is true because the earth is home to a vast variety of living organisms. From microscopic bacteria to large mammals, the planet is teeming with life in various forms. The diversity of living things is immense, ranging from plants, animals, fungi, and even single-celled organisms. This incredible array of life forms demonstrates the richness and complexity of the Earth's biosphere.

Explanation
The statement "There is no living things on earth" is incorrect. Earth is teeming with a wide variety of living organisms, including plants, animals, and microorganisms. From the smallest bacteria to the largest mammals, life exists in various forms on our planet. Therefore, the correct answer is False.

Explanation
The correct answer is Biosphere because the biosphere refers to the part of the Earth where living organisms exist. It includes all ecosystems and habitats on land, in water, and in the air. The biosphere is made up of a complex web of interactions between organisms and their environment, and it plays a crucial role in supporting life on Earth.

Explanation
Water evaporates continuously on the earth due to the heat of the Sun. The Sun's energy causes the water molecules to gain enough energy to break their bonds and escape into the air as water vapor. This process is known as evaporation and it is a crucial part of the water cycle. Evaporation occurs from various sources of water such as oceans, lakes, and rivers, as well as from plants through a process called transpiration. The water vapor then rises into the atmosphere where it can condense and form clouds, eventually leading to precipitation and the replenishment of water sources on Earth.

Explanation
The correct answer is 50. The stratosphere is the layer of the Earth's atmosphere that extends from the top of the troposphere (which is about 8-15 km above the Earth's surface) to an altitude of approximately 50 km. In the stratosphere, the temperature generally increases with altitude due to the presence of the ozone layer, which absorbs and scatters the Sun's ultraviolet radiation. This layer plays a crucial role in protecting life on Earth from harmful UV radiation.

Explanation
On the surface of the earth, we find land in some places and water in others. This is because the earth's surface is made up of different types of terrain, including landmasses and bodies of water such as oceans, seas, lakes, and rivers. Water covers approximately 71% of the earth's surface, while land covers the remaining 29%. This distribution of land and water on the earth's surface is due to various geological processes, including plate tectonics, erosion, and the water cycle.

Explanation
Asia is the correct answer because it is the largest continent in terms of both land area and population. It covers about 30% of the Earth's land area and is home to more than half of the world's population. Asia is known for its diverse cultures, languages, and landscapes, ranging from the vast deserts of Central Asia to the lush rainforests of Southeast Asia. With countries like China, India, Russia, and Indonesia, Asia is a powerhouse in terms of economic, political, and cultural influence on a global scale.