The Study Of Life
Chapter 1
Do Now:
• If a scientist hypothesizes that a vitamin
could extend a person’s life-expectancy,
then:
• 1) What is an experiment that can be
made to test this hypothesis?
• 2) What would be the independent
variable? Dependent variable?
• 3) Give one example each of qualitative
and quantitative data that can be collected
in this experiment
• https://www.youtube.com/watch?v=F8UF
Gu2M2gM
1.1 Introduction to Biology
• MAIN IDEA: All living things share the
characteristics of life.
The Science of Life
Biology = the science of life
1. Study the origins and history of life and
once-living things (evolution, cell
theory)
2. Study the structures of living things
(atoms, cells, body systems)
3. Study how living things interact
(ecology)
4. Study how living things function
(energy, respiration, photosynthesis)
What do biologists do? (Don’t copy)
• Study the diversity of life
– Classification of species
– Jane Goodall’s study of chimp behavior
• Research diseases
– Find causes, cures, and treatments
– Mary-Claire King is focused on finding the
genetic cause of breast cancer
• Develop technologies
– technology – use of science knowledge to
meet human needs
What biologists do cont’d (Don’t copy)
• Improve agriculture
– Genetically engineered crops
– Genetically altered livestock
– Organic pesticides
• Preserve the environment
– Protect species to prevent extinction
– Reproductive strategies
– Deal with issues of waste, pollution, global
warming, etc.
The Characteristics of Life
• How do we know something is, or
once was, alive?
• All organisms share the same
characteristics.
1. All organisms are made of one
or more cells.
• Cell – basic unit of structure and
function in all living things
• Can be unicellular (one cell)
• Can be multicellular (more than one
cell)
2. All organisms display
organization.
• Arranged in an orderly way
• Unicelled organisms – structures or
sections within cells that have certain
functions
• Multicelled organisms – specialized
cells  tissues  organs  organ
systems  organism
3. All organisms grow and
develop.
• Growth – addition of mass (cells,
structures)
– Ex: A flower stem becomes longer.
• Development – changes during an
organism’s lifetime
– Ex: A seed changes into a seedling
plant.
4. All organisms reproduce.
• Reproduction occurs among
members of the same species.
• Not necessary for the individual
organism’s survival, but instead for
the continuation of the species
5. All organisms respond to
stimuli.
• Anything that is part of an organism’s
internal or external environment is a
stimulus.
• A reaction to it is a response.
• Ex: A door slams, and you turn your
head toward the sound.
Label stimulus or response:
A fly bites you, and you swat at it.
A plant grows toward the sun.
6. All organisms require energy.
• From food
• Some organisms like plants
(producers) make their own food using
sunlight (photosynthesis) or chemicals
(chemosynthesis).
• Organisms that can not make their own
food (consumers) eat other organisms.
• Energy  growth, development,
performing life functions
7. All organisms maintain
homeostasis.
• Balance within an organism by
regulating internal conditions
• If something happens within or to an
organism to upset its normal state,
processes start that will restore its
balanced state.
• Ex: -Hibernation –A panting dog
–When you get a fever…
8. Organisms develop adaptations
that evolve over time.
• Inherited characteristics
• Help the survival of a species in
changing conditions
• Do not occur overnight or to an
individual
• Ex: camouflage, insect immunity to
pesticides
http://www.quia.com/pop/184568.html?AP_r
and=2020503416
1.2 The Nature of Science
• MAIN IDEA: Science is a process
based on inquiry that seeks to
develop explanations.
Definitions and Word Origins
• Science – study of our natural world
• Inquiry – seeking explanations; based
on unbiased observation and
experimentation
• Pseudoscience – “fake” science; areas
of “study” that have no real basis in
science
Science relies on evidence.
• Observations, data, experiments, etc.
• Theory – idea with a LOT of evidence in
support of it; many observations and
experiments with the same results
–studied by MANY different people
–ex: Big Bang Theory, evolution
• Pseudoscience –
–no evidence, data, or facts support it;
–Ex: astrology, palm reading
Science challenges accepted
ideas and questions results.
• Scientists welcome new ideas; findings
• Scientists often debate ideas
• Scientists look for accurate explanations
(if something new is discovered that
contradicts a known idea, it will be
researched further)
• Pseudoscience – will disregard ideas
that go against what they think is true.
Science tests claims.
• Ideas are researched thoroughly
according to specific procedures.
• Experiments can be repeated by
others, and can be retested for
accuracy.
• Pseudoscience – no research or
experimental procedures
Science undergoes peer review.
• Conferences and meetings are held
so scientists can review each others’
work.
• Scientists evaluate each other for
accuracy.
• Pseudoscience? NO!
Science uses the metric system.
• Same system all over the world, so
consistent
• SI = International System of Units
• Based on powers of 10, so easier to
do calculations
• Basic units:
Length = meter, mass = kilogram,
volume = liter, time = second
Science in Everyday Life
• Jobs useful to society:
–Doctors, nurses, pharmaceutical
employees, forensics lab workers,
environmentalists, genetic
counselors…..
EVERYONE should have a sense
of…
• Science literacy – ability to
understand issues of science
–Issues in daily life – cloning, stem
cell research, AIDS research,
drugs/alcohol…
• Ethics – moral values on certain
issues
1.3 Methods of Science
• MAIN IDEA: Biologists use specific
methods when conducting research.
Ask a Question
• Inquiry begins with an observation.
• Observations may pose questions
• Questions must be testable
Form a Hypothesis
• Educated guess
• Testable explanation of the question
Testable or Not?
• Catherine has seizures due to a lack
of sleep.
• Birds telepathically send each other
signals to each other so they can fly
in patterns.
Collect Data
• Information collected from observations
• Qualitative and quantitative
• Gathered through controlled
experiments or investigations
• Data organized in charts, tables, lists,
etc.; labeled and clear
Controlled Experiments
• A control group in an experiment is a
group used for comparison.
• The experimental group is the group
exposed to the factor being tested.
Experimental Design
• Independent variable—only one
factor in a controlled experiment can
change at a time
• Dependent variable—results from or
depends on changes to the
independent variable
• Constant – factor that does not
change
Analyze Data
• Organization of data, calculations
• Graphs make patterns easier to see
• Conclusions are drawn from the
interpretation of the data
• Determine if results support
hypothesis or not
Report Conclusions
• Research may be published in
journals, magazines, etc.
• Reviewers and other scientists
determine if findings are valid
• https://www.youtube.com/watch?v=i8wi0Q
nYN6s