Characteristics of Life Teacher comment: (you don’t need to write this down just read): Life we all think we know it when we see it, but we often find it hard to define. Yet, scientists have been able to determine what all life forms have in common and these are the characteristic of living things.

What is alive Organisms are living things. They can be a single cell such as a bacteria Or multicellular such as: plants, animals, fungi, & protists

All organisms are composed of cells Teacher comments: “Uni” means one and “Multi” means many. Unicellular organisms have only one cell and were the 1st living things on Earth. Bacteria and yeast are examples of singled celled organisms. Most multicellular organism have a variety of cells with different shapes that serve different purposes in an organism. Cells are the basic unit of structure and function of all living things Organisms are: Unicellular Multicellular Ameba Plant cells Animal nerve cell

All organisms use Energy use Energy is used to do everything necessary to stay alive and grow. Metabolism: Sum of all chemistry/ energy in a living thing. Left side: what does this bird use energy for? Teacher comments: We usually think of metabolism as how fast it takes us to digest and use the energy stored in the food we eat. But, metabolism is really the word used to describe all the chemical reactions in a cell or organisms and the energy involved in these reactions. Cardinal

Homeostasis Maintaining a steady internal environment. External environment is always changing. Teacher comments: “Homeo” means the same, and “Stasis” means state of , homeostasis is keeping the internal environment the same. This could be a cell keeping it’s pH within a certain range, or a person keeping his/her body temperature within a certain range. If homeostasis is not maintained an organisms will die. Left side: what else does your body do to maintain homeostasis?

All living things Grow & Develop All living organisms grow. Growth occurs by cell division and cell enlargement Organisms change over their life time/ develop

All living things Reproduce All species of organisms are capable of reproducing. Reproduction is essential to the species but not the individual. Reproduction is the transfer of genetic material from generation to the next Left side : What happens to a species if they do not reproduce?

All Living things have DNA DNA is a molecule that holds the genetic information of an organism DNA is passed on from one generation to the next as a result of reproduction

Visual summary List all the characteristics of living things and draw (a school appropriate) picture to represent each one (not copies from this PowerPoint.)