6.1 The Characteristics of Living Things Biologists use a list of characteristics to classify something as a living thing. 1. Made of Cells 2. Requires Energy 3. Maintain Homeostasis 4. Responds and adapt to their Environment 5. Reproduce 6. Grows and Develop

The Characteristics of Living Things All living things or once living things have these six characteristics. Anything without one of these six characteristics is nonliving. Living things are called organisms.

1. Made of Cells Organisms are made up of one or more cells. A cell is the basic unit of structure and function in living things. Cells = the All cells contain DNA! of life. “Building smaBlocks" Multicellular organisms will feature high levels of organization. Cells → Tissues → Organs → Organ Systems → Organisms

2. Requires Energy Sunlight is the source of energy for most living things. Plants use the energy in sunlight to make food, and animals get energy by eating plants or other animals that have eaten plants. All organisms need and use energy to live. Energy is the ability to do work.

3. Maintains Homeostasis It is extremely important for organisms to maintain Homeostasis – a constant internal condition . Organisms will DIE if their body temperature, fluid levels, waste levels and sugar levels get too high or too low!

4. Respond and adapt to their environment. Organisms react to change in their surroundings. Any reaction to change is called a response. For example: A bright light may cause you to blink. Even plants move to face the sun and when they open their flowers. It’s just that their movement is very, very slow. Organisms are adapted, or suited, to their surroundings. All organisms have features that help them survive in their surroundings. For example: fish have gills

5. Reproduce Organisms produce more organisms of their own kind. Reproduction allows organisms to continue living on the earth. Always includes the passing on of genetic material Includes both sexual and asexual reproduction.

6. Grows and Develop Living things change, or develop, during their lifetimes. One way organisms change is by growing. Living things may also change in appearance. For example: tadpoles and frogs All organisms grow and develop.

Summary Biologists use 6 characteristics to classify something as a living thing. 1. Made of Cells. 2. Requires Energy 3. Maintains Homeostasis 4. Respond and adapts to the surroundings 5. Reproduces 6. Grows and Develops All living things display all of the above characteristics.

Use a mnemonic sentence to remember: Cells, Energy, Homeostatic, Responds, Reproduces, Grows Cut every ham really really good. Carl echoed Henry’s really rare growl. Can every human risk rewarding growth?