What is Biology?

Biology is the study of….  Life!  In order to study life, we must know what life is.  We also study:  The interactions of living things  The interactions with the environment of living things  Problems 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:  Organization  Reproduction  Growth  Adaptation  Response  Homeostasis  Require Energy  Create 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!)

Reproduction  Reproduction is the production of offspring.  It can be:  Asexual-Can reproduce by itself  Sexual-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.

Response  A stimulus is something that causes an organism to react.  A response is a reaction to a stimulus.

Homeostasis  Homeostasis is the regulation of an organism’s internal environment to optimal conditions.  This can be voluntary or involuntary.

Require Energy  All 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 Waste  All living things create waste, or unusable matter and must dispose of it.  It can then be used by other living things.

The Scientific Method  In science we use a specific process, called the scientific method to gather information and answer scientific questions.

The Scientific Method  Observation  Prediction  Hypothesis  Experiment  Organizing and Analyzing the Data  Drawing 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 research  Re-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  

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

Technology and Society  Technology is the application of scientific research to society’s needs and problems.  Technology itself is not good or bad; we judge it based on how it is used.