Science Fundamentals

Science and the Scientific Method

• Science is an organized way of gathering and analyzing evidence about the natural world.
• Observation involves noticing and describing events or processes in a careful, orderly way.
• Inference is a logical interpretation based on what scientists already know.
• A hypothesis is a scientific explanation for a set of observations that can be tested in ways that support or reject it.

Experiments

• A controlled experiment is an experiment in which only one variable is changed.
• The independent variable is the variable that is deliberately changed (also called the manipulated variable).
• The dependent variable is the variable that is observed and that changes in response to the independent variable (also called the responding variable).
• A control group is a group in an experiment that is exposed to the same conditions as the experimental group except for one independent variable.

Data and Theory

• Data refers to detailed records of experimental observations, gathered information.
• A theory describes a well-tested explanation for a range of phenomena.

Biology and Life Processes

• Biology is the study of life.
• DNA is a genetic code written in a molecule that contains complex information to live, grow, and reproduce and is copied and passed from parent to offspring.
• A stimulus is a signal to which an organism responds.
• There are two types of reproduction: sexual reproduction (cells from two parents unite to form the first cell of a new organism) and asexual reproduction (a single organism produces offspring identical to itself).

Homeostasis and Metabolism

• Homeostasis is the condition in which all organisms need to keep their internal environment relatively stable, even when external conditions change dramatically.
• Metabolism is the combination of chemical reactions through which an organism builds up or breaks down materials.

The Biosphere

• The biosphere is the interconnected network through which all forms of life on Earth are connected, literally meaning "living planet".