How do we define biology Biology has different
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/unit 1/bio_ch 01_0021_ab_cells. html ee. Light microscope Electron microscope e-
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
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
Mitochondria in a cell release energy from sugars • Metabolism, cellular organization, homeostasis
A Venus flytraps 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
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