Unit 1: Introduction to Biology and the Nature of Science

Scientific Method

A systematic process used for scientific investigation, involving steps like observation, hypothesis, and testing.

Observation

Information detected using the senses (sight, hearing, touch, smell, taste).

Hypothesis

A possible, logical, and testable answer to a scientific question, based on existing knowledge.

Prediction

A statement that describes what will happen under certain conditions, often in "if/then" form.

Evidence

Data or information gathered to support or disprove a hypothesis.

Experiment

A scientific procedure to test a hypothesis by collecting evidence.

Falsifiable

Describes a hypothesis that can be proven false through evidence or observation.

Research

The process of gathering existing knowledge and information about a scientific topic.

Scientific Theory

A broad explanation for events, widely accepted as true, and supported by extensive evidence collected by many scientists.

Scientific Law

A statement that describes what always happens under certain conditions, unlike a theory, which explains why it happens.

***Example of a Scientific Law (Simple):

• Law of Segregation:

  • When plants make seeds, each seed gets only one gene copy from each parent, not both.

Cell Theory

States that all living things are made of cells.

• cells are the smallest unit of life, and all cells come from other cells.

Germ Theory of Disease

The scientific theory that proposes microorganisms cause many diseases;

• confirmed by Robert Koch and Louis Pasteur.

Experiment

A scientific investigation performed under controlled conditions to test a hypothesis and gather data.

Variable

A factor that can change in an experiment.

• The independent variable is changed by the scientist

• The dependent variable is observed for changes.

Control Group

The group in an experiment that does not receive the independent variable;

• used for comparison with the experimental group.

Sample Size and Repetition

Sample size refers to the number of subjects in an experiment.

Repetition means repeating the experiment to increase reliability of results.

Experimental Error

Mistakes or inaccuracies in measurements during an experiment,

• caused by humans or equipment,

  • leading to a margin of error in results.

Independent Variable

The factor that is changed or manipulated by the scientist in an experiment to test its effect.

Dependent Variable

The factor that is measured or observed in an experiment;

• it changes in response to the independent variable.

Experimental Group

The group in an experiment that receives the independent variable;

• used to compare the effects against the control group.