Chapter 1 Biology and You

Characteristics of Living Organisms Biology is the study of life. All living organisms share certain general properties that separate them from nonliving things. Properties of Life Cellular organization Reproduction Metabolism Homeostasis Heredity Responsiveness Growth and development

Branches of Biological Science Types of Biological Science Clip Botany Zoology Ecology

Themes of Biology Cellular Structure and Function Reproduction As you study biology you will repeatedly encounter the following seven themes. Cellular Structure and Function Reproduction Metabolism Homeostasis Heredity Evolution Interdependence

Cellular Structure and function All organisms are made of cells Cells are the smallest unit of life Organisms can have one cell or more than one cell

Reproduction All living things can reproduce Maintains the populations size Needed for survival of the species

Metabolism Metabolism - Sum of all chemical reactions Includes ways to obtain and use energy Digestion

Homeostasis Homeostasis – maintaining stable internal conditions regardless of external environment Internal environment vs. external environment Desert and tundra life

Heredity Passing on traits / genes to the next generation Parent  offspring Gene – basic unit of heredity

Evolution Small changes to a population over large periods of time

Interdependence Interactions between different species Beneficial or harmful

Section 3: Scientific Processes Observation is the act of noting or perceiving objects or events using the senses. Scientific investigations begin with observations. Observations cause scientists to ask questions about their observations.

Stages of Scientific Investigation Scientific investigations tend to have common stages. These stages are called the Scientific Method. There is more than one way to conduct an investigation. Scientific Methods or Scientific Processes are more accurate terms for the stages of scientific investigation.

Scientific Method Includes the following steps: Collecting Observations Asking Questions Forming a Hypotheses and making Predictions Hypotheses – educated guess Prediction – expected outcome of a test Confirming Predictions Experiment – planned procedure to test hypothesis Drawing Conclusions

Pieces of an Experiment Control Group – group that does not change Experimental Group – group that changes in 1 way Independent Variable – factor that is changed Dependent Variable – factor that is measured Independent Variable Dependent Variable

Scientific Explanations Theory – Set of related hypothesis that have been tested many times by many scientists