Animal / Plant Gas Exchange.

into energy, where carbon dioxide gas is created as a by-product or leftover. This is called respiration. This carbon dioxide is released into the air.Plants and algae breathe in carbon dioxide and carry it to every green cell, where it is used to transform sunlight into food. This is called photosynthesis. In this process, oxygen gas is created as a by-product or leftover, and is released into the air. Plants must have carbon dioxide to live. Animals must have oxygen to live. Both plants and animals give each other their by-products. We all live on leftovers. The diagram below show the circle of gas exchange between photosynthetic life and animal life.  Giving/Receiving: Gas Exchange is a system of Giving. Plants give oxygen to animals (including you), and animals give carbon dioxide to plants. Gas Exchange is also a system of Receiving. Plants receive carbon dioxide from animals, and animals receive oxygen from plants. So Gas Exchange is really a Gift Exchange, a life and death Gift Exchange. We can't live without each other. Some Details of the Exchange for AnimalsNot only flowering land plants give off oxygen. All the billions of green algae in the oceans do as well--any photosynthesis creates free oxygen as a by-product. Every life has to breathe, or respire. Here are the basic steps of respiration:  an animal breathes in or inhales air into the lungs oxygen in the air is transferred to the blood blood carries (circulates) the oxygen to every cell in the animal. each of those millions of cells then uses oxygen to burn food and     produce energy. as a cell produces energy, it also produces carbon dioxide as a     by-product or leftover. the cell transfers the carbon dioxide to the blood the blood carries carbon dioxide to the lungs; the lungs transfer the carbon dioxide to the air inside the lungs the animal breathes out, or exhales, releasing carbon dioxide       into the air.     Some Details of the Exchange for Plants and AlgaePlants breathe too, but not quite like animals. Plants do respire using oxygen in their cells, as animals do, but plants also inhale air to do photosynthesis, which means "putting-together-using-sunlight." Photosynthesis is the process of making food, which all life depends on. Here are the basic parts of  photosynthesis: the plant "inhales" carbon dioxide through its leaves. the plant "soaks up" sunlight through its leaves. the plant absorbs water through its roots.The plant circulates carbon dioxide and water to every living cell      with its sap; As each cell then produces food, using carbon dioxide and water plus sunlight, it produces oxygen as a by-product or leftover. The leaves "exhale," releasing the oxygen into the air. SummaryWithout plants, no animals.Without animals, no plants.We all depend on each other.