The characteristics of living organisms

All living things are made of cells. have DNA obtain and use energy. Excrete wastes grow and develop. reproduce. respond to their environment. adapt to their environment. Maintain homeostasis

To be considered alive, an object must exhibit all of the characteristics of living things. Not just a few. Remember there are nine characteristics all organisms have.

All living things are made up of one or more cells The cell is the smallest unit of life. –Some cells are made up of a single cell (unicellular). Most are too small to see. –Most living organisms are made up of many cells (multicellular). These are the organisms that you can see. Both multicellular organisms and unicellular organisms share all the characteristics of life.

All living things have DNA DNA is a universal genetic code shared by all organisms

Obtain and use energy ALL forms of life get the energy they use from the sun. Directly or indirectly. Plants and bacteria can capture this energy directly. (autotrophs) Animals use food as a source of energy but the food that animals eat comes from plants or animals that eat plants. (heterotrophs)

Autotroph

Heterotroph

Decomposer (heterotroph)

Excrete Wastes All organisms use and obtain energy and then get rid of waste products.

Grow and develop Most organisms grow into adult forms –Sometimes they grow and change greatly in size and appearance. –Some show little change as they grow.

Reproduce Asexual Reproduction- one parent creates genetically identical offspring Sexual Reproduction- two different parents contribute genetic material.

Respond to the environment All multicellular and unicellular organisms respond to stimuli in their environment. –Stimuli- anything that causes a change in an organism. –Response- the reaction to a stimulus

Adapt to the environment All living things have the ability to adapt to a favorable environment where they are able to reproduce. Adaptation- behavior or characteristic trait that helps a species survive.

Maintain Homeostasis Living things maintain homeostasis. –Homeostasis- a stable internal environment Ex: Humans are able to maintain a constant body temperature despite changes in the weather.