Chapter 1
Biology: The Study of Life
Biology
 The study of life
 Biologists study
o how living things interact with other living things
o how living things interact with their environment
o problems, such as disease and endangered species, and
propose solutions
Organism
 Anything that has all of the characteristics of life
Characteristics of life
1) Living things are made up of 1 or more cells that contain
DNA
2) Living things can carry out reproduction
a) Reproduction: Production of offspring
b) Species: group of organisms that can interbreed and
produce fertile offspring in nature
3) Living things grow and develop
a) Growth: an increase in the amount of living material and
the formation of new structures
b) Development: All of the changes that take place during
the life of an organism
4) Living things adjust to their environment
a) Environment: the air, water, weather, temperature,
organisms, etc. in an area
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b) Stimulus: anything in an organisms environment that
causes the organism to react
c) Response: the reaction of an organism to a stimulus
d) Example: Stimulus-cold winter without food
Response-bears hibernate
e) Homeostasis: Controlling an organism’s internal system to
maintain the conditions needed for survival
f) Example of homeostasis: When your body starts to
overheat, you sweat to cool yourself off
5) Living things need energy
a) Energy: the ability to cause change
b) Energy comes from food
6) Living things adapt and evolve
a) Adaptation: A body structure, behavior, or internal
process that allows an organism to respond to its
environment and survive to produce offspring
b) Evolution: The gradual change in a species through
adaptations over time
The Scientific Method
 The common steps that scientists use to gather information
and answer questions
1) Observe a problem and ask a question
2) Make a hypothesis
a) Hypothesis: an explanation to a question or problem
(educated guess) that can be tested
3) Conduct an experiment to collect data
a) Experiment: an investigation that tests a hypothesis
b) Experiments can involve
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i) A control group: the part of the experiment that
receives no experimental treatment
ii) An experimental group: The part of the experiment
that receives experimental treatment
c) In experiments, only one condition is changed at a time
i) an independent variable: the condition that is tested
ii) a dependent variable: the condition that changes due to
the independent variable and is measured
d) Data: information obtained from an investigation
(measurements, observations, etc.)
i) The data is analyzed in order to make conclusions
4) Publish data and conclusions in scientific journals for other
scientists to read
5) Form a theory
a) Theory: a hypothesis that is supported by a large body of
evidence
6) Develop new hypotheses based on the theory
7) Revise the theory as new experiments are done
Safety
 Safety is the number one concern when doing a lab
 Lab procedures in your book show safety symbols
o Safety symbol: symbol that warns you about a danger that
may exist from chemicals, electricity, heat, or procedures
o Be familiar with the safety symbols on p.1107
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Different kinds of data
 Quantitative data: numbers from measurements, counting,
etc.
o In biology, we use the metric system to make
measurements
 meter: length
 gram: mass
 liter: volume
 second: time
 degree Celsius: temperature
 Qualitative data: written description from observations
Ethics
 ethics: morals and values held by humans
 scientists might not consider all the possible applications for
their discoveries
 society must use ethics and take responsibility for using
science wisely
Technology
 application of scientific research to society’s needs and
problems
 technology improves our lives and the world around us
 but sometimes, technology can also hurt our lives or the
world around us