Biology is the study of….
Life!In order to study life, we must know what
life is.We also study:
The interactions of living thingsThe interactions with the environment of living
thingsProblems facing these living things and their
solutions
An organism’s environment is its’ surroundings:Air, water, weather, temperature, other
organisms, etc.
What Are the Characteristics of Life?
Let’s look at a few things and see if they are alive. We will then see what characteristics they share.
Characteristics of Life:OrganizationReproductionGrowthAdaptationResponseHomeostasisRequire EnergyCreate Waste
Organization
Organization is the orderly structure of an organism. All organisms are made of one or more cells.
Some microorganisms are made up of one cell, while humans and other large organisms are comprised of billions of cells (or more!)
ReproductionReproduction is the production of
offspring.It can be:
Asexual-Can reproduce by itselfSexual-Needs another organism to
reproduce
A species is a group of organisms that can interbreed and produce fertile offspring in nature.
Growth
Growth is the ability of an organism to increase in size and the formation of new structures.
Development is the series of changes that occur during the life of an organism.
Adaptation
Adaptation is the ability of an organism to make changes to better survive in its’ environment and be able to produce offspring.
Evolution is the gradual change in a species through adaptations over time.
ResponseA stimulus is something that causes
an organism to react.A response is a reaction to a
stimulus.
HomeostasisHomeostasis is the regulation of an
organism’s internal environment to optimal conditions.
This can be voluntary or involuntary.
Require EnergyAll living organisms require an
intake of energy in order to survive.Energy is the ability to cause
change.This energy comes from food, which can
be created or consumed.
Create WasteAll living things create waste, or
unusable matter and must dispose of it.It can then be used by other living
things.
The Scientific MethodIn science we use a specific process,
called the scientific method to gather information and answer scientific questions.
The Scientific Method
ObservationPredictionHypothesisExperimentOrganizing and Analyzing the
DataDrawing Conclusions
Observation Observation is when we use our 5 senses
to see and record things. Observation only involves sensing and
recording, NOT drawing conclusions.
We can use tools to help us to observe. We can record with writing, drawings,
photos, measurements, or sound recordings.
What are the most useful senses in science? Which are the least?
Predictions A prediction is a logical statement of what
will occur in a given situation. After an experiment we never change a
prediction, we just evaluate if it was correct.
Some great scientific discoveries have happened by accident or from predictions being wrong
Hypotheses A hypothesis is a testable explanation or
prediction which uses the words “If” and “Then”.
Example: If ______________ happens, then __________ will happen.
It is more than just a guess and is based on observations.
Experiments An experiment is a procedure used to test
a hypothesis. It includes several essential parts:
Dependent Variable Independent Variable Experimental Group Control Group
Dependent and Independent Variables An independent variable is what we are
testing. The dependent variable is what we are
measuring. It is dependent on what we are testing.
Let’s try some examples: Which grows faster, a plant in the sun or a
plant in the dark? Which is faster, a lion, a tiger, or a bear? Who likes cookies more, Cookie Monster or Mr.
Harlacher?
Experimental and Control Groups We divide an experiment into two or more groups. A control group is when everything is run as
normal. Nothing is changed. An experimental group has only one thing
changed. Why do we change only one thing?
Let’s look at some examples: Which grows faster, a plant in the sun or a plant in the
dark?
Does an athlete perform better drinking Gatorade or water?
If students study more, will they get better grades?
Organizing and Analyzing Data Next, data must be collected from the
experiment. Once again we draw no conclusions here.
This means collecting data and organizing it in a way that makes sense. We often use a graph or table for this. Some types are: Table-Simply organizes the data.
Bar graph-Shows the results in columns
Line graph-shows the data in a mathematical plane with axes.
Pie chart-Shows all the data at once in comparison to the whole.
Pictogram-Similar to a bar graph, but with pictures to represent data.
Scatter Plot- Shows the data points only on a graph,
Drawing Conclusions An examination of the data is made to
evaluate if the hypothesis was correct or not. It does not matter if the hypothesis was
“right” or “wrong”. The result is valuable either way.
Mathematical analysis such as an average/mean, standard deviation, or t-test can be used to see if any difference between the control and experimental group(s) was significant.
A conclusion is then drawn and stated as to whether the hypothesis was correct or not.
Next Steps…Scientists can then:
Publish their researchRe-test to examine if the results are
consistent.Revise or change their hypothesis and
experiment again.Look for sources of error in their process.
What if an Experiment Can’t be Run? Sometimes due to moral, ethical, practical,
or financial constraints an experiment cannot be run.
We would then use the process of correlation- which should be a reliable association between two or more events.
However correlation does not prove causation. Since we are not isolating one variable, we can’t be sure that one causes the other.
Let’s look at some good and bad correlations…
The Good, the Bad, and the Ugly People who eat McDonald’s every day are
more likely to be obese. Backed up by scientific data that people who
eat McDonald’s every day have more health problems than those who don’t.
Bad A soccer team that practices 30 minutes more a
day than a rival has a better record.
Ugly http://
www.tylervigen.com/view_correlation?id=359 http://
www.tylervigen.com/view_correlation?id=7
Scientific Habits Curiosity Skepticism Openness to New Ideas Intellectual Honesty Imagination and Creativity
What is a Scientific Theory or Law? A scientific theory is when a particular
hypothesis has many experiments and observations supporting it over time It is an explanation of natural phenomena that
has a large body of scientific evidence to support it.
A scientific law is when a certain explanation has accrued enough scientific evidence that it is assumed to be true.
In science however, we can never absolutely prove something; all we can do is fail to disprove it and refine it.
Types of Information In science we need to be able to classify
observations, results, and other information into types of information.
There are two main types of information: Quantitative Qualitative
Science and Society Science and the results of scientific
research are never inherently good or bad. It is how they are used or applied that is judged by the ethical values or moral values of a society.
Think of nuclear power: Nuclear bombs can cause much damage and
devastation. Nuclear power plants currently supply 48% of
New Jersey’s electricity as an alternative to oil or coal power plants.
Think of morphine: It can eliminate pain in those who have serious
medical problems It is highly addictive and can cause dependence
easily
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