MRS GREN

• M - Movement

  R - Respiration

  S - Sensitivity

  G - Growth

  R - Reproduction

  E - Excretion

  N - Nutrition
• Movement - All living things move. They move to obtain food, to escape from predators, to mate, to avoid disease, to avoid injury, and to maintain body temperature.
• Respiration - A chemical reaction that releases energy for all life processes. In multicellular organisms, respiration usually involves the breakdown of glucose with the use of oxygen, producing energy that can be used by cells and it produces carbon dioxide as a waste product.
• Sensitivity - The ability to detect a change in the environment, or to respond to a stimulus.
• Growth - All living things grow. Growth is possible because respiration provides excess energy for organisms to use to grow. Excess energy can produce new cells and tissues which leads to growth.
• Reproduction - The creation of a living thing from an existing organism. The simplest form of reproduction is the division of one cell into two. In large, multi-cellular organisms, reproduction can occur sexually or asexually.
• Sexual reproduction requires two organisms.
• Asexual reproduction is where one organism produces a new organism entirely by themselves.
• Excretion - All organisms produce wastes that need to be removed. This term is used to define the removal of waste products from an organism. Some waste products are urine, carbon dioxide and dead cells. If waste products stay inside an organism, they can become toxic.
• Nutrition - Refers to feeding. It is the process of providing food to the body.
• Herbivores are animals that can eat plants and get nutritions from them.
• Carnivores consume other animals and eat meat only.
• Omnivores eat both animals and plants.
• Plants get their nutrition by making glucose in a chemical process called photosynthesis. Can only occur in the presence of sunlight and oxygen gas is released as waste.