"It may be drawing it from the surrounding fish cells, or it may have a different type of respiration such as oxygen-free breathing, which typically characterizes anaerobic non-animal organisms." ...

Some animals have evolved to survive without oxygen in extreme environments. Creatures like **Hydra** can switch to anaerobic ...

Metabolism close metabolismAll the chemical reactions in the cells of an organism, including respiration. is the term used for all the chemical reactions that happen inside an organism's body.

Animals depend upon plants as an energy source. Chemicals in food are broken down in respiration to create energy stores that can be used by the cell. Animal cells have a basic structure.

Both need water and air. We often think of animals using oxygen and glucose for cellular respiration and producing carbon dioxide. Similarly, we might think of plants using carbon dioxide and sunlight ...