Chapter 1: What
is Biology?
What is Biology?
»Bio-: means life
• – ology: Study of
• Biology is the study of
life/living things
Branches of Biology
• Zoology: study of animals
• Botany: study of plants
• Paleontology: study of ancient
life
Why Study Biology?
• Live longer, healthier lives
• Use evidence to learn about the natural
world
• Pleasure of learning
• Understanding the “web of life” (all
organisms are connected to each other)
• Understand/control our future
– Why things happen and what could happen in
the future
Themes in Biology
• Flow of energy through systems
– Cell  Organism  Biosphere
– Powers all life processes
• Interaction of systems
– Interacting with the environment
• Unity within diversity
Themes in Biology
•
•
•
Homeostasis: regulation
of an organism’s internal
environment to maintain
survival
Evolution: gradual
change in a species
through adaptations
over time
Biology is always
expanding and changing
the field of study
Characteristics of All
Living Things
1. Made up of cells
– Unicellular (made of one cell) vs.
multicellular (made up of many
cells)
2. Highly organized
3. Use energy
– Ex: metabolism
Building chemical substances
Energy required
Energy released
Breaking down chemical substances
4. Growth and Development
• Growth: increase in
the amount of
material (size) and
the formation of new
structures
• Development: all of
the changes that
take place during an
organism’s lifespan
5. Have a life span
6. Reproduction: sexual vs. asexual
– Needed for the survival of a species
– Most multicellular species reproduce
sexually
7. Respond to a stimulus (ex: blink/flinch
when something is thrown at you)
8. Adaptations: evolution
– Variation of traits that are inherited
9. Maintain homeostasis: internal balance
Matter Organization
molecules
elements
atoms
• 6 most abundant elements in all living
things
– Carbon, Hydrogen, Oxygen,
Nitrogen, Sulfur, and Phosphorus
• Organelles and cells
– Organelles are mini “organs” found
in every cell
Organisms
Few
unicellular, multicellular, or
colonial
organ systems
organs
Many
tissues
cells
Species
Populations
Communities
Ecosystems
Biomes
Biosphere
Bell Ringer:
1. List the 9 characteristics that classify a
mushroom as a living thing.
2. What is the name for a collection of living
matter enclosed by a barrier that separates is
from its surroundings?
a. cell b. cell culture c. cell fractionation d. DNA
3. What is the name for a combination of chemical
changes that builds up or breaks down material in an
organism?
a. homeostasis
b. metabolism
c. sexual reproduction
d. cell culture
The Scientific Method:
• http://dsc.discovery.com/tvshows/mythbusters/videos/surrealgourmet-hour.htm
Scientific Method
• common steps used to gather information
and answer questions (8 steps)
1. make observations: use your senses
2. state the problem
3. gather information
4. make a hypothesis: an explanation for a
question or a problem that can be tested
– has to be able to be tested can be
disproved
– is not a guess or a fact (sometimes
cannot be 100% proven accurate)
5. test the hypothesis through an experiment:
procedure that tests a hypothesis by
collecting information under controlled
conditions
6. collect and gather data: information
obtained from the experiment
7. draw a conclusion: was the hypothesis
correct or incorrect?
8. publish results in scientific journals
– allows other scientists to repeat experiment
– Ex: Redi’s and Pasteur’s experiments
(disproved spontaneous generation)
Theory
• Well-supported hypothesis
• Well-tested explanation
• Can be revised or replaced by
another theory
Controlled Experiments
• involve two groups: control group
and experimental group
• control: standard by which all
conditions are kept the same
• experimental group: the test group in
which all conditions are kept the
same except for the single condition
being tested
–only one condition is changed at a
time
–independent variable: what is being
changed (manipulated variable)
• affects the outcome of the
experiment
• dependent variable: results from
the change of the independent
variable (responding variable)
–changes to it depend on changes
made to the independent
variable
• Not all experiments are controlled (ex:
field studies)
Qualitative Data
• Using the senses to describe
observations and gather
information
• What you see, smell, taste,
touch…etc.
• Describe using words
Quantitative Data
• Experiments yield
•
numerical data
• System of measurement
(SI): metric system
– Base units:
• length  meters (m)
• mass  grams (g)
• volume  liters (L)
• time  seconds (s)
• temp  °C
– Based on multiples of
10
Prefixes:
– kilo (1000)
– hecto (100)
– deca (10)
– deci (0.1 or 1/10)
– centi (0.01 or 1/100)
– milli (0.001 or 1/1000)
Science and Society
• Knowledge gained through research is
never good or bad
• Attempts to explain how and why things
happen
• Science is objective: can be tested and
measured
• Society is dealing with the subjective
– Social, moral, and ethical concerns
(right vs. wrong)
• Pure science
–Gaining knowledge through
discovery
• Applied science
–Technology that applies knowledge
to fit society’s needs and problems
–Involves making improvements in
human life
• Inductive reasoning
– Reasoning about something from a
set of facts
– Start with a specific statement or
fact make a general statement
• Deductive reasoning
– Suggesting something from a set of
facts or general rules
– Start with a general rule or fact 
make a specific statement from that
general rule
Microscopes
• Light vs.
electron
• Electron: SEM
vs. TEM
Lab Techniques
• Cell cultures-make copies
• Cell fractionation
–Separate into parts
Bell Ringer:
1. Place the following steps of an experimental
investigation in the correct order:
__ Form a hypothesis
__ Record and analyze results
__ Set up a controlled experiment
__ Ask a question
__ Draw a conclusion
2. What type of microscope allows light to pass
through the specimen and uses two lenses to
form an image?
a. TEM
b. electron
c. compound light
d. SEM
3. The type of microscope that focuses beams of
electrons on specimens is the
a. compound
22
b. electron c. scanning
d. compound
light