Biology is the study of life.
--Bio means life
--ology is “the study of”
Think of Biology as being a two dimensional
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subject…
1st it is structured on a size scale ranging from molecular (such as the
molecules that make us up) all the way to global (think of global warming
and other weather patterns that effect life around the globe.)
2nd it is enormous in its diversity. Look around you right now and see if there
is any diversity in this classroom. What do you think? Now, imagine you are
in the park taking a walk…what about diversity there? Get the picture??
Is there a method to the madness?? How do we separate one
living thing from another?
How do we define LIFE???
Properties of Life:
1. All are organized (order)—
Start with the molecule, cell, tissue, organ, organ system, organism
Some organisms skip some of the in between steps.
2. All can metabolize (process energy)–
That is…they can chemically break down the food they consume into useable
parts. Think about the food you eat…do you use it directly? Or do you have to
“convert” it first?
3. All can reproduce—
All organisms are born with the ability to reproduce but not all do. Some are
naturally non-fertile and others are “made” this way.
4. All can regulate their internal environment– (homeostasis)
temperature regulation is important to bodily function as well as hormone
regulation and insulin regulation
5. All grow and develop–
start out as a strand of DNA and eventually become an organism through cell
division .
6. All respond to their environment-Why would it be important to respond? What does this characteristic allow us
to do?
7. All organisms evolve—
This means all organisms change over time.
This can be a life long evolution or a seasonal evolution.
Life is organized into three domains:
1. Bacteria
2. Archaea
3. Eukarya
These domains each have specific organism characteristics that place them in the
domain. For instance, Bacteria and Archaea have prokaryotic cells (contain no
membrane bound organelles) and Eukarya have eukaryotic cells(contain many
membrane bound organelles, particularly the nucleus).
Bacteria – “true bacteria” consists of organisms that can make you sick and make
objects they inhabit “nasty” (picture your toilet if you don’t clean it for about a month)
They are single celled and have a special coating on the outside that protects them
from being digested by white blood cells in the body. They are prokaryotes.
E. coli is just one example of a common bacteria
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Domain Archaea/i/anammox_africa.jpg
-similar to bacteria.
-used to be grouped with bacteria
- are prokaryotic cells like bacteria
-features different from bacteria separate them
into two domains
-archaeaic organisms often live in environments too
harsh for other organisms to survive in.
-”bacteria” living in Yellowstone National Park hot springs live in extreme
heat…around 200-240* F.
- organisms found living along heat vents at bottom of ocean live in dark,
cold environments where little or no other life exists.
-Use elements as a source of energy such as sulfur and nitrogen.
Domain Eukarya-organisms have eukaryotic cells.
-grouped into four kingdoms.
Protista Kingdom—
-amoeba, euglena, paramecium and other aquatic microorganisms
Fungi Kingdom—
- mushrooms and molds
Plantae Kingdom—
-plants
-280,000 known plants
http://www.canadiangeographic.ca/atlas/Images/Gl
ossary/Invertebrate.jpg
Animalia Kingdom—
-animals
-50,000 know vertebrates
(animals with a backbone)
-750,000 known insects
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Science is a process…a way to find out more about the world
around us.
The word Science comes from the latin verb meaning “to know.”
So we can say science is a way of knowing.
Many sciences exist in the world:
Psychology—knowing about the psych or mind
Sociology– knowing about the social structures
of the world
Gerontology– the science of aging
Biology—the study of life
And the list could go on and on. It is important to “think out of
the box” when talking about science. It is much broader in its
definition than biology is. For instance, consider this flashlight…
Would you use a science process to figure out why it doesn’t work?
Biologists use a process to find out more about living things.
This consists of a series of steps that lead to conclusions.
These steps are called the SCIENTIFIC METHOD:
1. Make observations about the world around you.
2. Ask a question about these observations.
3. Form a hypothesis about your question. An “educated guess”
or tentative answer to your question based on what you know.
--many times we use a hypothesis to solve everyday problems
and don’t even think about it. Remote example.
4. A prediction is formed based on deductive reasoning. This
is usually an “if…then” statement. Meaning “if this happens…
then this is probably true.”
5. Predictions can be tested by doing experimentation.
This is the “fun” part of science!!
Experiments are designed to test hypothesis.
There must be some comparison involved. For this reason,
experiments always consist of two parts:
Control—the part of the experiment that remains neutral.
Whatever changes in the variable does not change in the control.
Variable—the part of the experiment that changes. The test is
actually administered to the variable. Variables can only differ
from the control by one factor. More than one difference
makes it difficult to determine what is causing changes in the
variable during the experiment.
The control serves as the comparison for the variable. We can
show a change took place when the variable is different from
the control after the experiment takes place.
Sometimes the results of the experiment don’t match the
prediction. If this happens, you can rewrite your prediction and
retest!!! Isn’t science wonderful!! You are never wrong!
Imagine how simple classes would be if you could change all
your wrong answers on tests and resubmit them for a better
grade!!!
6. Conclusions are drawn at the end of experiments to help
make it easier to understand what happened.
Since science is not definite, you can never prove anything,
just falsify or support your hypothesis!!
7. Publishing is important to the scientific method. Can you
think of a reason why it would be important to publish the
results you get from an experiment?
Is all printed material dealing with science believable?
How can you separate the “real” science from the stuff that is
really “out there?”
Two things are important here.
Ask yourself, “Is this biologically possible?”
“Can I perform an experiment to show this is possible?”
(in other words, is it testable?)
True Science is biologically possible and can be tested.
-Effects of drugs on cancer cells
-Effects of herbicides on weeds
Pseudoscience is not biologically possible and cannot be
tested.
-goat people discovered in remote mountain village
-3 year old girl gives birth to baby boy
What about things like bigfoot and UFO’s and Lochness??
How about ghosts and poltergeists and little green men??
Can they be tested?
Can we prove they don’t exist?
We put them in a “grey” area of science that is neither true
nor pseudo.