Biology - The study of life
• Life is diverse
• All living things share certain characteristics:
•
•
•
•
•
Made up of cells
Need energy
Reproduce
Respond to environment
Have DNA
All living things are interrelated!!
Six Criteria of Science :
Consistent,
Observable,
Natural,
Predictable,
Testable,
Tentative.
"CONPTT"
Consistency : The results of observations
and/or experiments are reasonably the
same when performed and repeated.
1. Green plants will grow towards a light source.
2. Walking under a ladder will cause bad luck.
Observability : The event or evidence of the
event, can be observed and explained. The
observations are limited to the basic human
senses or to extensions of the senses.
1. Some plants can eat meat.
2. Extraterrestrial beings have visited Earth.
Natural : A natural cause (mechanism)
must be used to explain why or how the
event happens.
1. Green plants convert sunlight into energy.
2. People can walk through walls.
Predictability : Specific predictions can
be used to make foretell an event. Each
prediction can be tested to determine if
the prediction is true of false.
1. Students who attend class do better than students
who do not attend class
2. If you are a "Scorpio", your horoscope for today is
"You'll be saying 'I feel rich !' Lunar position
highlights back pay, refunds, correction of
accounting error."
Testability : the event must be testable
through the processes of science, and
controlled experimentation.
1. The Bermuda Triangle causes ships and
planes to sink and disappear.
2. Dogs are more social than cats.
Tentativeness : Scientific theories are
subject to revision and correction, even to
the point of the theory being proven
wrong. Scientific theories have been
modified and will continue to be modified
1.
2.
The number of human chromosomes was once
"known" to be 48, but is now considered to be 46.
We know that the world began about 6000 years ago,
and nothing will change that.
Scientific Method
• What is it?
– An objective and logical process by which
we ask questions and find answers
• Why do we need it?
– To promote open and honest exchange of
data with others; to share what we learn
Steps to the Scientific Method:
Step 1: Purpose of experiment
First – make an observation
- Use your senses to take in new
information and ask questions
- Draw information from previous
experience; consider what you
already know!
Next -use what you observe and
what you already know to
formulate a hypothesis
- A hypothesis is an educated
guess about a scientific question
Format: “If……then…..because…..”
• Example: IF we increase the
temperature of the water THEN
the breathing rate of the fish will
increase BECAUSE breathing rate
is dependent upon temperature
Steps 2-5: Create experiment to
test hypothesis
Step 2 - There is a control (what
naturally happens, what we observe)
- There is a variable (what we change
and then measure the effects of)
Step 3 - There are two types of variables:
– Independent Variable: variable that is
changed during the experiment
• Example: water temperature
– Dependent Variable: data that is collected
through observation and measurement
• Example: Breathing rate
• Example: Fish need to be in room
temperature water (control). How
would it affect their breathing rate
if we lowered the temperature 10
degrees (variable)?
• What is the independent variable?
Dependent variable?
Step 4 – list all materials used in
experiment (bullet points)
Step 5 – step-by-step procedure
list of how you set up your
experiment (numbered)
Steps 6 & 7: Collect Data and Analyze
Results
– Collect data using a table then present data
using a chart (typically line or bar chart)
– Analyze results:
• Summarize results (1-2 sentences, use
data)
• State why you believe you got your results
• List any possible sources of error in
experiment
• Step 8: Conclusions
– 1-2 sentences summarizing your experiment
– Did your data support your hypothesis? Why or
why not?
– What would you do differently next time?
– Additional questions you may have after
experiment is completed
• Step 9: Peer Review
– As you evaluate the work of others, consider
the following questions:
• Is the experiment repeatable?
• Do you see any possible errors (additional
variables)
• Ask clarifying questions (things that need to be
explained better)
• Are results verifiable?
Be prepared to answer these questions
from your peers