CH. 2 Science Basics

Biology: the scientific study of life.

What makes something scientific?

Observations, data, inferences, and generalizations are important to scientific understanding.

CH. 2.1 Discovery Science

Scientific explanations are based on OBSERVATIONS & DATA that are collected from EXPERIMENTS.

Qualitative Data: descriptions & drawings

Quantitative Data: measurements, #s

Ch. 2.1: Discovery Science

Inference: Logical conclusion based on observations.

Observation: doorbell rings

Inference: Someone is at the door

Ch. 2.1 Science of Discovery

Generalization: Many specific observations are put together to reach a general conclusion.

Ex: Women have a longer lifespan than men.

Look for patterns in data.

Ch. 2.2: Hypothesis based research

Scientific MethodObservation --> Question --> Hypothesis -->

Prediction --> Test/Experiment

If test does not support hypothesis: rework hypothesis or test.

If test does support hypothesis: More tests are needed!

Ch. 2.2

Hypothesis: well defined answer to a scientific question. An explanation on trial.

• Hypothesis must be TESTABLE with an experiment.

• Must be “falsifiable” … proved false by a given result.

• Stated in “if … then” format

Ch. 2.2: Testing a hypothesis

Controlled Scientific ExperimentAll conditions (variables) in experiment are kept the

same, except for the one condition (variable) you are testing for.

Independent variable: Condition you are manipulating to answer the question.

Constant/Controlled conditions: Conditions kept the same for all test subjects

Dependent Variable: Condition that may vary at the end in response to the experiment; the results

Ch. 2.2: Testing a hypothesisControlled Scientific Experiment

Experimental Groups: Groups you are testing your independent variable on.

Control Group: Comparison group in an experiment; independent variable is left out; “natural” or “normal” condition.

(If you are testing to determine what color of light is best for photosynthesis … you need a group of plants grown under natural sunlight for comparison (to establish a baseline for results)

Ch. 2.3: Evaluating Evidence

Evidence: a collected body of data and observations from experiments.

A good scientific experiment produces REPEATABLE evidence.

Ch. 2.3 Theories

Theory: well tested explanation supported by data from many, many experiments

– Can be revised in light of new results.

Ch. 2.3 Models

Models: physical, mental, or mathematical representations of processes or objects.

• Used for things too small, big, or complex to visualize.

• Explains observations; can be used to make predictions; matches new observations.