chapter 1: the science of biology section 1: what is science? ccs biology mr. bogusch bill nye -...
TRANSCRIPT
Chapter 1: The Science of Biology
Section 1: What is Science?
CCS Biology
Mr. Bogusch
Bill Nye - Science
What Science Is and Is Not
• Science as a Way of Knowingo Science is an organized way of gathering and
analyzing evidence about the natural worldo Science is a process
o Science only deals with the natural world
o Science collect and organize information in an orderly way
o Science explanations are based on evidence, not belief
The Goals of Science
• One goal of science is to provide natural explanations for events in the natural world.– Science uses these explanations to understand
patterns in nature to make useful predictions
Science, Change, and Uncertainty
o Science is always changing; it never stands still
o Uncertainty is part of what makes science exciting
Scientific Method
• 1. Observing and Asking Questions• Observation – the act of noting and
describing events or processes in a careful, orderly way
• Philosopher Arthur Schopenhauer: “think something that nobody has thought yet, while looking at something that everybody sees.”
For example, researchers observed that marsh grass grows taller in some places than others. This observation led to a question: Why do marsh grasses grow to different heights in different places?
Scientific Method
• 2. Inferring and Forming a Hypothesiso Inference- logical interpretation based on what
scientists already knowo Hypothesis – scientific explanation for a set of
observations that can be tested in ways that support or reject it.
Inference can lead to a hypothesis, or a scientific explanation for a set of observations that can be tested in ways that support or reject it.
What inference scan you make about the marsh grasses?
– For example, researchers inferred that something limits grass growth in some places. Based on their knowledge of salt marshes, they hypothesized that marsh grass growth is limited by available nitrogen.
Scientific Method
• 3. Designing Controlled Experimentso Controlled experiment – testing a hypothesis with only one
variable is changed
o Variable – factors that can change– For example: light, time, availability of nutrients
o Controlling variableso Independent variable – (manipulated variable) the variable
that is changed
o Dependent variable – the variable that changes in response to the independent variable
– The variable you measure
– For example, the researchers selected similar plots of marsh grass. All plots had similar plant density, soil type, input of freshwater, and height above average tide level. The plots were divided into control and experimental groups.
– The researchers added nitrogen fertilizer (the independent variable) to the experimental plots. They then observed the growth of marsh grass (the dependent variable) in both experimental and control plots.
Scientific Method
o Control Group – receives no experimental treatment
• Experiment Group – receives experimental treatment; one independent variable is changed in
– Scientists record experimental observations, gathering information called data. There are two main types of data: quantitative data and qualitative data.
Scientific Method
• 4. Collecting and Analyzing Datao Data – information from detailed experimental records
o Quantitative Data – numbers obtained by counting or measuring
– Ex. Number of plants per pot, plant height, plant width
o Qualitative Data – descriptive observations that usually cannot be counted
– Ex. Plant growing sideways or upright
– Sources of Error – researchers must be careful to avoid errors in collecting data
– This graph shows how grass height changed over time.
Scientific Method
• 5. Drawing Conclusionso Scientists use experimental data as evidence to
support, refute, or revise the hypothesis being tested, and to draw a valid conclusion.
o When Experiments are not possibleo It is not always possible to test a hypothesis with an
experimento Animal behavior in the wild
o Ethical concerns (especially with humans)
