Introduction to Biology – Unit 1A

Chapter 1 – The
Study of Life
1.1 Introduction to Biology
1.2 The Nature of Science
1.3 Methods of Science
1.1- Introduction to Biology
Essential Questions:
 What is Biology?
 What are the benefits of studying Biology?
 What are the characteristics of living
The Definition of Science:
 An
accumulation of
known facts.
 The
search to explain of
 Bio
= “life” and –ology
= the study of
What Do Biologists Do?
Study the diversity of life (Jane
Research Disease (Mary-Claire King)
Develop Technology – using science
to meet human needs (Charles Drew)
Improve agriculture (Joanne Chory)
Preserve the environment (Lee Anne
Look at the picture…
Answer the
questions below:
 Name three living
 Name five nonliving things.
 What makes a
thing living or
non-living? Write
a list of criteria:
1. Made of one or more cells:
Single-cell organisms
have everything they
need to be selfsufficient.
 In multicellular
specialization increases
until some cells do only
certain things.
2. Displays different levels of
Both molecular and cellular organization.
 Living things must be able to organize
simple substances into complex ones.
Cells – the smallest
unit of life.
Organ system
Organism - any
complete living thing.
3. Grows and develops:
Growth - the increase in size of an
 Development – the process of natural
changes during the life of an organism.
4. Reproduces:
All living things use DNA (a genetic
code) as a blueprint.
All living things reproduce in one of the
following ways:
Sexual reproduction - Producing offspring by the
joining of sex (male/female) cells.
 Asexual reproduction - Producing offspring (cloning)
without the use of sex cells.
Reproduction is not essential for the
survival of individual organisms, but must
occur for a species to survive.
5. Responds to their environment:
A behavior is a complex
set of stimulus and
– anything that
causes a response.
 Response – the reaction to
the stimulus.
 Stimulus
Living things will make
changes in response to a
stimulus in their
6. Requires energy:
Living things take in energy and use it for
maintenance and growth.
 Metabolism – any chemical process in an
 Ex:
 Ex: digestion
 Ex: respiration
7: Maintains homeostasis
Homeostasis – regulation of an organism’s
internal conditions to maintain life.
8. Adapt to their environment:
Adaptations are traits giving an organism
an advantage in a certain environment.
 It can be:
physical trait (a body part)
 A physiological trait (body process)
 A behavior
Variation of individuals is important for a
healthy species.
In Summary: Living Things…
Are made of one or more cells
Have different levels of organization
Grow and develop
Responds to the environment/stimulus
Use energy
Maintain homeostasis
Adapt to the environment
Discussion Questions:
Do some non-living things have some of
the characteristics of life? Give an
 Name some non-living things that use
 Name some non-living things that grow.
1.2 – The Nature of Science
Essential Questions:
 What are the characteristics of scientific
 What are the differences between science
and pseudoscience?
 Why is scientific literacy important?
The Nature of Science
Science – a body of knowledge based on
the study of the natural world
 Theory – an explanation of natural
phenomenon supported by many
observations and experiments over time
 Law – describes (but usually doesn’t
explain) relationships under certain
What Science Does…
Makes observations and draws
 Expands knowledge
 Challenges accepted theories
 Questions results
 Tests claims
 Undergoes peer review
Science is Everyday Life
Literacy – to be scientifically literate, you
must combine knowledge with critical
thinking skills
 Ethics – a set of moral principles or
1.3 – Methods of Science
Essential Questions:
 What are the differences between an
observation and an inference?
 What are the differences between a control,
independent variable, and dependent variable?
 What are the scientific methods a biologist
uses for research?
 Why are the metric system and SI units
Observation v. Inference
Observation – a direct method of
gathering information in an orderly way. It
usually involves the 5 senses!
 Inference – the process of combining
what you know with new information to
draw a logical conclusion. It involves
using your brain and intuition (6th sense).
Steps of The Scientific Method
1) Question or problem
2) Research problem – use dependable
3) Form a hypothesis – an educated guess.
If we (IV) then (DV) happens
4) Experiment to test hypothesis (use variables)
controlled variable - the baseline or starting point from
where you measure. This group doesn’t have the
independent variable applied.
independent - the variable you have control over or
usually what you think will affect the dependent
variable. Also known as the experimental group
dependent - the variable you measure in the
experiment. It is called dependent because it "depends"
on what happens to the independent variable.
constant – other factors that are the same in the control
and experimental groups
5) Analyze data – use data
tables, graphs and charts.
6) Conclusion - accept or
reject hypothesis
7) REPEAT – the more
times you get the same
outcome the better!
IV. Tools of the Scientist:
the mind and senses
the Scientific Method
other written information
microscope and other
metrics - International System
(SI Units) of measurement
Let’s practice…
Smithers thinks that a special juice will
increase the productivity of workers. He
creates two groups of 50 workers each
and assigns each group the same task
(in this case, they're supposed to staple
a set of papers).
Group A is given the special juice to
drink while they work. Group B is not
given the special juice. After an hour,
Smithers counts how many stacks of
papers each group has made. Group A
made 1,587 stacks, Group B made
2,113 stacks.
1. Control Group?
2. Independent Variable?
3. Dependent Variable?
4. What should Smithers's
conclusion be?
5. How could this experiment
be improved?
Homer notices that his shower is
covered in a strange green slime.
His friend Barney tells him that
coconut juice will get rid of the
green slime.
Homer decides to check this this
out by spraying half of the shower
with coconut juice. He sprays the
other half of the shower with
water. After 3 days of "treatment"
there is no change in the
appearance of the green slime on
either side of the shower.
6. The initial observation
7. Control Group
8. Independent Variable
9. Dependent Variable
10. What should Homer's
conclusion be?
Bart believes that mice exposed to
microwaves will become extra strong
(maybe he's been reading too much
Radioactive Man). He decides to
perform this experiment by placing
10 mice in a microwave for 10
seconds. He compared these 10
mice to another 10 mice that had not
been exposed.
His test consisted of a heavy block of
wood that blocked the mouse food.
he found that 8 out of 10 of the
microwaved mice were able to push
the block away. 7 out of 10 of the
non-microwaved mice were able to
do the same.
11. Control Group?
12. Independent Variable?
13. Dependent Variable?
14. What should Bart's
conclusion be?
15. How could Bart's
experiment be improved?
Krusty was told that a certain itching
powder was the newest best thing on
the market, it even claims to cause
50% longer lasting itches. Interested
in this product, he buys the itching
powder and compares it to his usual
One test subject (A) is sprinkled with
the original itching powder, and
another test subject (B) was sprinkled
with the Experimental itching powder.
Subject A reported having itches for
30 minutes. Subject B reported to
have itches for 45 minutes.
16. Control Group?
17. Independent Variable?
18. Dependent Variable?
19. Explain whether the
data supports the
advertisements claims
about its product.
Lisa is working on a
science project. Her task
is to answer the
"Does Rogooti (which is
a commercial hair
product) affect the speed
of hair growth".
Her family (mom, dad,
Bart, and Maggie) is
willing to volunteer for
the experiment.
Describe how Lisa would
perform this experiment. In
your description,
1. Write a hypothesis,
2. Identify the control
3. Name the Independent
4. Name the Dependent
5. List in bullets - any
supplies you might
6. List in numbered steps the procedure you
would take.