Chapter 1 The Study of
Life
1.1 Introduction to Biology
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Biology is the study of life

There are many
different types of
living things;
many (or most)
haven’t been
discovered yet.
Snowy the albino echidna
2
Biology is the study of life

In Biology you will study


the features of living
things and how they work.
the interactions of living
things with each other and
the nonliving world.
3
What Biologists Do





Study the diversity of
life
Research diseases
Develop technologies
Improve agriculture
Preserve the
environment
4
Characteristics of Living Things
Alive or not?
5
Characteristics of Living Things

Living things are
made of cells.
The cell is the basic
unit of life.
All living things are
composed of one or
more cells containing
DNA (the hereditary
material) that function
in an organized way.
6
Characteristics of Living Things

Living things display
organization.


Atoms form molecules,
groups of molecules form
cells, cells form tissues,
different tissues working
together form organs, organs
working together form organ
systems and organ systems
working together to support
an organism.
Structure fits function is a
major theme in biology. 7
Characteristics of Living Things

Living things grow and
develop.
Growth is the addition
of mass while
development is the
process of changes that
occur throughout the
life of an organism.
8
Characteristics of Living Things

Living things reproduce.
Organisms reproduce
and pass along traits
from one generation to
the next. For a species
to continue to exist,
reproduction must
occur.
Reproduction can be
asexual or sexual.
9
Characteristics of Living Things

Living things respond to
stimuli.
All organisms live in
constant interface with
environment: air, water,
weather, temperature,
other organisms…
10
Characteristics of Living Things


Stimulus: condition in
the environment that
causes an organism to
adjust
Response: reaction to a
stimulus
11
Characteristics of Living Things



Living things maintain
homeostasis.
Many responses
organisms make are
internal regulations
make to maintain a
“steady state”
Homeostasis:
maintaining steady
state, takes energy.
12
Characteristics of Living Things

Living things require energy.
 Energy is the ability to do
work and is required for all
life processes.
 Organisms get energy from
food.
 Plants, some Protists, and
some bacteria make their
own food in the process of
photosynthesis (producers).
 Animals, fungi, some
Protists and some bacteria
need to consume food
(consumers).
13
Characteristics of Living Things

In living things
adaptations evolve over
time.
Adaptation are inherited
changes that occur over
time to enable an
organism to respond to
stimuli and better
survive IN AN
ENVIRONMENT.
14
Characteristics of Living Things

Gradual accumulation
of adaptations over time
is EVOLUTION
Fourth marking period
we study evolution and
find that some
organisms evolve
slowly (horse) while
others evolve within our
lifetime (bacteria).
15
A Systematic Approach
The scientific method is a
systematic approach used in
scientific study, whether it is
chemistry, physics, biology, or
another science.
It is an organized process used
by scientists to do research,
and provides methods for
scientists to verify the work
of others.
A Systematic Approach (cont.)
The steps in a scientific method are repeated until
a hypothesis is supported or discarded.
A Systematic Approach (cont.)
An observation is the act of gathering information.
– Qualitative data is obtained through
observations that describe color,
smell, shape, or some other physical
characteristic that is related to the five
senses.
– Quantitative data is obtained from
numerical observations that describe
how much, how little, how big or how
fast.
A Systematic Approach (cont.)
A hypothesis is a
tentative
explanation for
what has been
observed.
An experiment is a set
of controlled
observations that test
the hypothesis.
A Systematic Approach (cont.)
A variable is a quantity or condition that can have
more than one value.
– An independent variable
is the variable you plan to
change.
– The dependent variable
is the variable that
changes in value in
response to a change in
the independent variable.
A Systematic Approach (cont.)
A control is a standard for comparison in the
experiment.
A conclusion is a judgment based on the
information obtained from the experiment.
– A hypothesis is never proven, only supported or
discarded.
– A model can be used to make predictions.
Theory and Scientific Law
A theory is an explanation that
has been repeatedly
supported by many
experiments.
– A theory states a broad
principle of nature that has
been supported over time by
repeated testing.
– Theories are successful if
they can be used to make
predictions that are true.
Theory and Scientific Law (cont.)
Section 1-3
A scientific law is a
relationship in nature
that is supported by
many experiments,
and no exceptions to
these relationships
are found.