3. What is science?
One of the first things you should understand is that
scientific knowledge is always changing. Why?
➔because scientists are constantly testing, debating,
and revising scientific explanations of events in the
natural world.
4. What is science?
The nature of science:
The term science is usually defined as the
❖ use of evidence to construct testable explanations
and predications of a natural phenomena.
❖ Generating knowledge.
The word science can refer to constantly growing and changing
body of knowledge that the process of science generates
5. How is science different form other ways
of explaining how the world works?
➢Science deals only with the natural world.
➢Scientists collect and organize information in an orderly way.
➢Scientists propose explanations based on evidence and understanding, not belief.
6. Goals of science
One goal of science is to
❖ provide natural and testable explanations for events in the natural world.
Also aims to
❖ use explanations supported by data to understand patterns in nature, and to make
useful predictions about natural events.
7. Scientific methodology
Scientific methodology involves
✓ observing and asking questions,
✓ forming hypotheses,
✓ conducting controlled experiments,
✓ collecting and analyzing data,
✓ drawing conclusions.
There isn’t a single, cut-and-dried “scientific method.”
But there is a general style of investigation we call scientific methodology,
which is a fancy way of saying “the way science works
10. Scientific Methodology: Hypothesis
Inference: a logical interpretation based on
Hypothesis: a tentative scientific explanation that can be
what scientists already know
tested further
11. Scientific Methodology: Designing controlled experiments
Testing hypotheses often involves designing experiments that
measure factors that can change, or variables.
12. Scientific Methodology: Designing controlled experiments
It is important to control variables
because if several variables are
changed, researchers can’t easily
tell which variable is responsible for
any results they observe.
The variable deliberately changed is
called the independent variable.
The variable that is observed and
that changes in response to the
independent variable is called the
dependent variable.
13. Scientific Methodology: Designing controlled experiments
A control group is exposed to the
same conditions as the
experimental group except for
changes in the independent
variable. Scientists always try to
reproduce or replicate their
observations by setting up several
control and experimental groups,
rather than just a single pair.
14. Scientific Methodology: Analyzing conclusion
Scientists observe their experiments,
gathering two main types of data.
Quantitative data
are numbers obtained by counting or
measuring.
Qualitative data
are descriptive and involve
characteristics that cannot usually be
measured.
16. Scientific Theories
In science the word theory applies to
a tested highly reliable scientific explanation of events in the
natural world that unifies many repeated observations and
incorporates durable, well-supported hypotheses that enable
scientists to make accurate predictions.
17. When experiments aren’t possible?
Not all hypotheses can be tested by experiments.
Animal behavior researchers, for example, might propose hypotheses about how
groups of animals interact in nature. These hypotheses are tested by field observations
designed to disturb natural behavior as little as possible.
Sometimes ethics prevent certain types of experiments. For example,
in medical research, when a chemical is suspected as a cause of cancer,
researchers do not purposely expose volunteers to the chemical.
They study people who have already been exposed, using those who have not as the
control group.
18. What are the different branches of science?
Life science
oBiology ➔
the study of all
living things
Earth science
oThe study of
Earth and
Space
including:
• Landforms
• rocks and
• soil
Physical science
oChemistry
physics
• Interactions of
matter and
energy
19. Life science
o Biology ➔ the
study of all living
things
Birds, insects, animals,
trees, human beings
Bacteria, Fungi.
20. Earth science
o The study of Earth
and Space
including:
• Landforms
• rocks and
• soil
22. Can you define biology??
The study of all living things
➢ you will learn the
origins and history of life and once-living things.
➢ You will also learn structures, functions, and interactions
of living things.
biologists concluded that
all living things have
certain characteristics
23. Assignment
What are the characteristics of life?
Write a short paragraph on the benefits you can get from
studying biology.
