So that it can sustain different life that requires different environments. Angler fish, for example, require a dark and cold environment to thrive while tuna require a light and warm environment.
Answer:
Carbon dioxide from the air is used to produce food for plant growth. Carbon moves from plants to animals when animals eat the plants. Also, Carbon moves from living things to the atmosphere. Each time you exhale, you are releasing carbon dioxide gas (CO2) into the atmosphere.
The burning of fossil fuels also releases carbon dioxide into the atmosphere.
B. Resistance is the tendency for materials to oppose the flow of electric charges.
The term for blue skin caused by lack of oxygen is cyanosis. One is said to be cyanotic when presenting with this discoloration.