Earth is made up of four different parts that all work together to make life on this planet possible. The four difference parts (or spheres) are called the atmosphere, lithosphere, hydrosphere, and the biosphere. ATMOSPHERE:Earth’s atmosphere is a thin layer of gases and tiny particles, made up of approximately 78% of nitrogen gas, 21% of oxygen gas, and the remaining 1% of the atmosphere contains argon, water vapour, carbon dioxide along with trace amounts of other gases. These gases combined together are commonly known as air.The atmosphere acts like a blanket of gases that surrounds the planet and keep Earth’s temperature within an acceptable and sustainable range.Additionally, Earth’s atmosphere absorbs and filters out some ultraviolet (UV) radiation coming from the sun. UV radiation can destroy living cells and cause skin cancer.As part of the matter cycle, carbon dioxide, oxygen gas, nitrogen gas, and water (vapour) either starts at or goes through the atmosphere. Therefore, without the atmosphere, only the simplest life forms would be able to survive on Earth, most of the other species would be unable to live on Earth.LITHOSPHERE:Lithosphere acts like the “skeleton” of Earth, all of the other spheres are built on top of it.It refers to the rocks and minerals that are found on Earth.All of the landforms that those rocks and minerals created are part of the lithosphere, including the mountains, volcanoes, and the land that humans live on.HYDROSPHERE:The hydrosphere contains all the water on, above, and below Earth’s surface. This includes the oceans, rivers, groundwater, ice, and clouds.Surprisingly, Earth’s oceans contain 97% of the planet’s water, leaving just 3% as fresh water (water with low concentrations of salts). Water on Earth changes from one form to another as it moves through the hydrological cycle.BIOSPHERE:Biosphere is the highest level of ecological organization; it is known as the zone of life on Earth. The term “biosphere” is used to describe the place where living things are found within the lithosphere, atmosphere, and hydrosphere.It is the sum of all the ecosystem and consists of all the parts of Earth where life exists, which includes both terrestrial and aquatic ecosystems.