Characteristics of Life Listen to recordings (by clicking on the speaker icon) or read “notes” under slide.

What is alive Organisms include: bacteria, plants, animals, fungi, & protistsOrganisms include: bacteria, plants, animals, fungi, & protists Does not include viruses.Does not include viruses. –Viruses are not cells. –Viruses are proteins and nucleic acids Ebola virus: Referred to as a hemorrhagic virus because it causes hemorrhages in its victims.

All organisms are composed of cells –Cells are the basic unit of structure and function of all living things –Organisms are: –Organisms are: Unicellular Multicellular

Organization Living things are all highly organized.Living things are all highly organized. –Organisms take substances from environment and organize them in complex ways. Cross section of a root showing root hairs on the outer surface.

Energy use Energy is used to maintain organization. Energy is used to maintain organization. Metabolism: Sum of all chemistry/ energy in a living thing.Metabolism: Sum of all chemistry/ energy in a living thing. Cardinal Think: what does this bird use energy for?

Homeostasis Homeostasis Maintaining a steady internal environment.Maintaining a steady internal environment. –External environment is always changing. Baby Sea Lion Think: what does your body do to maintain homeostasis?

Growth All living organisms grow.All living organisms grow. –Growth occurs by cell division and cell enlargement Bacteria dividing after growth stage.

Reproduction All species of organisms are capable of reproducing.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 Think: What happens to a species if they do not reproduce?

Answer these questions in your summary 1.List all the characteristics of living things. 2.Entropy is the natural tendency towards disorder. What do living things do that counters entropy? 3.What is the chemistry/ energy use of living things called? 4.Why are viruses not alive? 5.Name 2 ways organisms maintain homeostasis (other than those mentioned in this lecture).