What is science?
A way of observing, a way of thinking, and
a way of knowing about the world.
Science is a process not a thing.
Science rarely proves anything, but aims
for the best understanding to make useful
Which of the following questions
could be answered by science?
1. Is an elephant beautiful?
2. Is it ethical to test beauty products on
3. How does smoking damage your lungs?
4. Do people watch too much TV?
General Stages of Scientific Investigation
1. Asking a Question
2. Collecting Information/Making observations
3. Inferring and forming a hypothesis
4. Designing a controlled experiment to test the
5. Collecting/Analyzing Data (qualitative vs.
6. Drawing Conclusions
If the hypothesis is supported scientists will
retest the hypothesis.
If the hypothesis is not supported scientists
will modify or form a new hypothesis.
How do we make a valid
Inference and imagination can lead to a
If marsh grass has abundant nitrogen in the soil,
then it will grow taller than marsh grass without
nitrogen in the soil.
Variables and Controls
Variables – factors that change
Independent – you manipulate (what you
Dependent – change in response to the
independent variable (variable that is measured)
Control Group – used for comparison
Nothing is changed
You recently planted a pot of daisies, but
they are becoming wilted and seem to be
dying. You would like to find out what is
happening, and what you can do to save
1. What is the question you are trying to answer?
2. What would your hypothesis be?
3. Design a controlled experiment to test this
Krusty was told that a certain itching
powder was the newest best thing on the
market, it claims to cause 50% longer
lasting itches. He buys the itching powder
and compares it to his usual product. One
test subject (A) is sprinkled with the
original itching powder, and another test
subject (B) was sprinkled with the
experimental itching powder. Subject A
reported having itches for 30 minutes.
Subject B reported to have itches for 45
1. What is Krysty’s hypothesis?
2. What was Krusty’s control group?
3. The variables in this experiment are the type
of itching powder and the itches experienced
by subjects. Which is the independent and
which is the dependent variable?
4. Does the Krusty’s data support his
Review Question cont.
• Lisa is working on a science project. Her task is
to answer the question: "Does Rogooti (which is a
commercial hair product) affect the speed of hair
growth". Her family is willing to volunteer for the
experiment. Bart uses Rogooti, while Maggie
uses no hair product. After 1 week Bart’s hair
has grown 2cm and Maggie’s hair has grown
1. What could Lisa’s hypothesis be?
2. Who is Lisa’s control group?
3. Which is the independent variable and which is the
4. Was Lisa’s hypothesis supported or rejected?
In science we measure using metric units
Why do scientists need a common system
SI conversions practice
1. 1m = _____cm
2. 2500mL = _____L
3. _____s = 5400ms
4. 0.017g = _____mg
Draw a line graph to display the data
Time (Days) Height of flower (cm)
You have performed an
determine which of the
thermostats in 3 different
classes is most efficient.
To do this you timed
how long it took each
room to reach a stable
started the time when
you turned on the heat
and recorded the
temperature every 5
minutes for 25 minutes.
Use the data below to
construct a line graph
showing each room on
the same graph.
0 16 16 16
5 17 17 17
10 19 20 17.5
15 20 23.5 18
20 21 25 18.5
25 20.5 26 18
Good scientists share scientific attitudes, or
habits of mind, that lead them to exploration and
• Peer review
• Look for bias, oversights, or mistakes
• Ensures highest standards are met
• Publish articles after peer review
• These communications spark new
What is a scientific theory?
A theory unites and explains a broad range of
A theory is a well-supported scientific
explanation that makes useful predictions.
No Theory is considered the absolute truth
The possibility always remains that future
evidence will be uncovered and cause a
scientific theory to be revised or rejected.
Science and Society
• Scientific questions involve the society in which
we live, our economy, and our laws and moral
• Pure science does not include ethical or moral
• Example: Biologists try to explain in scientific
terms what life is and how it operates, but
science cannot answer questions about why
life exists or what the meaning of life is.
What is biology?
The study of life
Bio – life logy – study of
Patterns that connect all forms of life:
Composed of one or more cell.
Reproduce – sexual vs asexual
Able to obtain and use energy
Maintain a stable internal environment
Universal genetic code
Grow and develop
Biology in Your World
Biologists are constantly working to solve
Preserving our environment
Improving the food supply
Understanding the human genome