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Organized way of using evidence to learn about the natural world; also, the body of knowledge that scientist have built up after years of using this process.


Use of one or more of the senses-sight, hearing, touch, smell, and sometimes taste-to gather information.


Evidence; information gathered from observations.


Logical interpretation based on prior knowledge and experience.


possible explaination for a set of observations or possible awnser to a scientific question.

Spontaneous Generation

Hypothesis stating that life could arise from nonliving matter.

Controlled Experiment

A test of the effect of a single variable by changing it while keeping all variables the same.

Manipulated Variable

Factor in an experiment that a scientist purposely changes; also known as independent variable.

Responding Variable

Factor in an experiment that a scientist wants to observe, which may change in response to the manipulated variable; also known as a dependent variable.


Well-tested explanation that unifies a broad range of observations.


Science that seeks the understanding of the living world.


Collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic unit of all forms of life.

Sexual Reproduction

Process by which cells from two different parents unite to produce the first cell of a new organism.

Asexual Reproduction

Process by which a single parent reproduces by itself.


Set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes.


A signal to which an organism responds.


Change in a kind o fan organism over time; process by which modern organisms have descended from ancient organisms.


Process by which organisms maintain a relatively stable internal environment.

Metric System

Decimal system of measurement based on certain physical standards and scaled on multiples of 10.


Device that prodices magnified images of structures that are too small to see with the unaided eye.

Compound Light Microscope

Microscope that allows light to pass through a specimen and uses two lenses to form an image.

Electron Microscope

Microscope that forms an image by focusing beams of electrons onto a specimen.

Cell Culture

Group of cells grown in a nutrient solution from a single original cell.

Cell Fractionation

Technique in which cells are broken into pieces and the different cell parts are separated.

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