How do we define life?

Properties of Life Are organized, and are made of one or more cells (Cellular Organization) Maintain stable internal conditions (Homeostasis) Are capable of Reproduction Exhibit Growth and development

Respond to their environment (Responsiveness) Pass traits to offspring (Heredity) Use energy. Metabolism is the sum of all chemical reactions carried out in an organism.

Examples Hummingbirds feed almost constantly to supply energy to their racing wings and hearts. Metabolism

A butterfly emerges from a cocoon. Growth and Development

A Venus Fly Trap closes its leaves when an insect lands on it. Responsiveness

A bacterium divides into new cells every 15 minutes. Reproduction

A child inherits the same color eyes as his parents. Heredity

An elephant's large ears allow the blood in the ears to be cooled by as much as 10 degrees. Homeostasis

A pill bug rolls into a ball when touched. Responsiveness

Earthworms are made of specialized cells, such as digestive cells, muscle cells, skin cells, etc. Cellular Organization

A female frog lays many eggs at a time. Reproduction

A toad burrows in the mud during hot weather to avoid water loss. Homeostasis

An amoeba is composed of a single cell. Cellular Organization

A child inherits cystic fibrosis from his parents. Heredity

Mitochondria in a cell releases energy from sugars. Metabolism

Stimulus or Response? The bell rings at the end of a class period Your dog runs into the kitchen when you open a can A paramecium backs up and moves away when it encounters an obstacle. A plant grows toward the window A baby hears a loud noise You pull your hand away after touching the hot oven

Branches of Biology Biochemistry: chemistry of life Ecology: how organisms interact with each other and their environment Cell biology: life on the cellular level Genetics: how organisms pass traits to their offspring

Evolution: changes in organisms over time Microbiology: microscopic organisms Botany: plants Zoology: animals