Answer:
Biosphere
Explanation:
The Biosphere
[Earth from space] Everything around you that is alive is found in the fourth sphere, the Biosphere. It includes plants and animals that live on land, in the air, and in the water within all three of the other spheres. Clearly, the biosphere is closely related to the atmosphere, lithosphere, and hydrosphere. Changes in any of these spheres affect the biosphere.
[Polar bear on ice] Similarly, human activities have effects on the other spheres as well. For example, driving a car releases carbon dioxide into the atmosphere, increasing the overall temperature of the Earth. The increase in temperature has resulted in the melting of glaciers and a rise in sea levels in the hydrosphere. The rise in sea levels may have an impact on the biosphere, forcing populations of organisms along coastal regions to relocate.
[Hand with pictures of carbon cycle: planes, cars, industries produce carbon dioxide which is removed by plants that produce oxygen in return] The living organisms that are in the biosphere influence the other spheres in many ways. One influence is when organisms modify the atmosphere to make it conducive to life. For example, plants remove carbon dioxide and produce oxygen.
Another example is when organisms produce materials used by humans and other living organisms. Also, when plants and animals die and decompose, some material enters the atmosphere, while other organisms may fossilize and re-enter the lithosphere.
[Recycle symbol made up of images of the sky, grass, and rock surface] The exchange of materials and other interactions between spheres never stop. Just as the human body relies on interrelated systems, like the digestive, nervous, and cardiovascular system, the Earth also has systems that are interdependent to each other. The Earth’s exterior has four principal systems: the atmosphere, lithosphere, hydrosphere, and biosphere. All perform critical roles that, together, support life.
