British Sign Language Glossaries of Curriculum Terms

BSL Environmental Science Glossary - Nitrogen cycle definition

Definition: The nitrogen cycle describes the way nitrogen moves through the atmosphere, the land, animals, people etc. For example, the atmosphere contains nitrogen (N₂) - when lightning occurs the energy can transform the nitrogen in the air into ammonia and drive it down into the soil. Plants have special bacteria that can absorb nitrogen from the atmosphere, again converting it into ammonia. Humans. plants and animals have nitrogen in our bodies - when we die, our bodies decay and the nitrogen inside us returns to the soil. Plants have special bacteria that convert ammonia into nitrates. A different type of bacteria converts nitrates in plants which release nitrogen back into the atmosphere. This continual movement of nitrogen is called the nitrogen cycle.