Cycles of Life Vocab

  • evaporation - the process in which a liquid changes into a gas
  • condensation - the process in which a gas changes into a liquid
  • precipitation - any form of water particles — rain, snow, sleet, or hail
  • groundwater - precipitation that seeps into the ground
  • runoff - precipitation that flows downhill across the surface of the ground
  • water cycle - the continuous movement of water between Earth's surface and the air, changing from liquid to gas and back to liquid
  • carbon cycle - the continuous transfer of carbon between the atmosphere and living things
  • nitrogen cycle - the way nitrogen moves between the air, soil, plants and animals
  • carbon dioxide - a gas containing carbon and oxygen
  • photosynthesis - a process where plants use carbon from carbon dioxide to make sugars, starches and proteins
  • proteins - a part of our muscles and many cell structures; also contains the element nitrogen, which is used to make muscles, nerves, skin, bones, blood, and digestive juices
  • soil - plants get nitrogen by absorbing it from the soil
  • ammonia - plant proteins are broken down by decomposers when they die; they are turned in the nitrogen-containing substance ammonia
  • nitrites - nitrogen-containing substances created by bacteria from the nitrogen in the air
  • nitrates - bacteria turn nitrites into nitrates, which also contain nitrogen
  • denitrifying bacteria - bacteria that turns nitrates back into nitrogen gas
  • nitrogen-fixing bacteria - bacteria that grows on pea and bean roots; they give the plants the nitrogen they need; they turn nitrogen gas into the air into nitrogen-containing substances plants need to make their proteins