Chapter 1 Section 1

Characteristics of Living Things All living things posses the following characteristics

Biologists have identified about 1.5 million species

Cells Cells are life’s basic unit of structure and function All living things are made of cells Cells are extremely small

The Cellular Basis of Life All organisms are made up of cells Multicellular organisms have specialized cells The organism’s survival is based upon the functions and interactions of the cells.

Cellular Order

Reproduction Sexual - Cells from two different parents unite to form the first cell of the new organism asexual reproduction- A single parent produces off spring that are identical to itself

Reproduction

DNA and genes DNA is the chemical responsible for inheritance It is located in genes on chromosomes in the nucleus

Inheritable Characteristics

Growth and Development Cells divide for growth and development. Most cells undergo “differentiation” which causes them to take on special roles required for that organism. Skin cells, neurons, and blood cells are all specialized cells.

Growth & Development

Energy and Life Metabolism is the net effect of what an organism builds up and breaks down Producers trap the sun’s energy to produce food for entire ecosystem Consumers eat (consume) the food made by the producers This transfer of energy is not efficient

Energy

Interaction with the Environment No organism is completely isolated from its surroundings. Stimuli cause an organism to respond.

Response to Environment

Regulation Organisms regulate their internal body environment to maintain homeostasis Internal environment stays about the same; while external environment changes

Homeostasis

Adaptation Organisms possess adaptations that can be passed on to their offspring Some adaptations make them more able to survive

Adaptation