How do we define biology?

Biology has different branches 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

Biology has different branches, cont’d Evolution: changes in organisms over time Microbiology: microscopic organisms Botany: plants Zoology: animals

Microscopy http://www.classzone.com/cz/books/bio_07/resources/htmls/animated_biology/unit1/bio_ch01_0021_ab_cells.html e- Electron microscope Light microscope

Life is Diverse

Properties of Life

Living Things 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, homeostasis

A butterfly emerges from a cocoon. Development

A bacterium divides into new cells every 15 minutes Reproduction

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

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 into the mud to prevent water loss during extended periods of dry weather. Homeostasis, Responsiveness

An amoeba is composed of a single cell. Cellular Organization

A child inherits cystic fibrosis from her parents Heredity

Metabolism, cellular organization, homeostasis Mitochondria in a cell release energy from sugars Metabolism, cellular organization, homeostasis

A Venus flytrap traps an insect between its leaves. Responsiveness

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