End of topic checklist Excretion is the removal of waste (often toxic) substances that have been produced from chemical reactions inside the body, such as carbon dioxide and urea in animals. Growth is the permanent increase in body size and dry mass of an organism, usually from an increase in cell number or cell size (or both). Respiration is the chemical process in which glucose is broken down inside cells, releasing energy and producing carbon dioxide and water. Sensitivity refers to the detection of changes (stimuli) in the surroundings by a living organism, and its responses to those changes. Nutrition is the taking in of substances for use in the body as food or to make food. Homeostasis is the maintenance of a constant internal environment, such as body water content and body temperature. Reproduction is the production of new organisms.
The facts and ideas that you should know and understand by studying this topic:
❍ All living organisms show the eight characteristics of life at some point in their lives.
❍ The characteristics of life are: movement, respiration, sensitivity, homeostasis,
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CHARACTERISTICS OF LIVING ORGANISMS
growth, reproduction, excretion and nutrition.
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