Science is a search for truth.
Truth is the way things are.

Scientists are NOT holders of truth. They are skeptics! They are always questioning what we think we understand.

The Scientific Method:

1. State the problem
2. Research the problem
3. Form a hypothesis
4. Test the hypothesis
5. Draw Conclusions

Designing an Experiment

Scientific theory - a generally accepted explanation of a concept or a broad explaination of a natural phenomena.

Example: The Cell Theory

Example: The Law of Gravity

 
Can a scientific "truth" change?

Just ask a Coelacanth or Pluto

The coelacanth made scientists change their "truth".

With Pluto, scientists decided to change their "truth".

 
Science involves communication.

Everything scientists write is an argument, from a memo, to a journal publication, to a grant proposal--each is a document written to convince.

An ability to argue clearly and convincingly is essential. Today's professional, scientist or not, must have presentation skills of all types from writing, to speaking, to preparing effective electronic posters for meetings.

• Always write in complete sentences.
• What is a "first person statement"?
• Paragraph evaluationEssays and Evaluation
• Research papers evaluation
• Understanding Scientific Papers

When experiments are performed there are almost always some observations where questions like "how fast", "how far", or "how much" must be answered. The only way to answer these questions is through measuring.

Because of this, numbers in science will always have "units". These units are just as important as the numbers when communicating observations. Never write a number without its units.

A "standard" is something that is used as a comparison for measuring. Two things are important for any standard:

• A standard must be available for everyone to use when checking measurements.
   
  • A standard should be something in nature that is the same all over the earth.
   
• A standard must never vary.

Unit Conversion Tables

SI Base Units

• Length - meter
• Mass - kilogram
• Temperature - ^oC
• Amount - mole
• Time - second

Derived Units - combinations of base units.

• Area - length squared
• Volume - length cubed

  1 ml = 1 cm³

  1 liter - 1 dm³

• Density - mass / volume

  D_H2O = 1 ^g/_cm³

SI Prefixes

• mega - 1,000,000
• kilo - 1,000
• hecto - 100
• deca - 10
• base unit - 1
• deci - 0.1
• centi - 0.01
• milli - 0.001
• micro - 0.000001

English system vs SI system

• These "ballpark" relationships are close enough for every-day conversion.
   
  • 1 yard ≅ 0.9 meter
  • 1 mile ≅ 1.5 kilometer
  • 1 inch ≅ 2.5 centimeter
  • 1 pound ≅ 0.5 kilogram
  • 1 quart ≅ 1 liter

Lab Safety: Everyone Is responsible!

Lack of pre-lab preparation is the main threat to safety in our lab. If you and your group are unprepared, you will be unsure of yourself, waste time, and have a good chance of making a mistake that leads to a problem.

The proper use of laboratory equipment is important for both safety and preservation of equipment

 
A microscope is an instrument that produces an enlarged image of an object. Biologists use microscopes to study things that are too small to be seen with the unaided eye.

Using Graphs To Display Data:

Scientific observations (data)

Graphs make data trends easier to see

Line Graph How To

Reading scientific graphs

Biology is the study of life. There are many related studies, known as life sciences.

Exactly what life is and how it starts is one of the most difficult problems in science. There is no simple statement that can be used to define life.

 
The only sure way to define life is to describe its characteristics.

The 7 characteristics of life:

1. Living things are composed of cells.

• Single-cell organisms have everything they need to be self-sufficient.
   
• In multicellular organisms, specialization increases until some cells do only certain things.

• Molecular organization:
   
  • Living things must be able to organize simple substances into complex ones.
   
• Cellular organization:
   
  • cells
  • tissues
  • organs
  • organ systems

• Energy is needed for maintenance and growth.

• Living things respond to a stimulus in their environment.
   
• A behavior is a complex set of responses.

• Cell division - the orderly formation of new cells.
   
• Cell enlargement - the increase in size of a cell.
   
• Cells grow to a certain size and then divide.
   
• An organism gets larger as the number of its cells increases.

• Reproduction is not essential for the survival of individual organisms, but must occur for a species to survive.
   
• Types of reproduction:
   
  • Asexual repoduction - producing offspring without the use of gametes.
     
  • Sexual reproduction - producing offspring by the joining of sex cells.

• Adaptations are traits giving an organism a survival advantage.
   
• There are variations in the traits of individuals within a species.
   
• It is the environment that determines whether a trait is an advantage or a disadvantage.

Biochemistry is the chemistry of life.

All life is dependent on the chemical reactions between molecules. Life begins with the simplest molecules and builds more and more complicated chemical interactions.

Life on Earth is carbon-based

Cells are 90% water

The composition of the human body is 90% oxygen, carbon, and hydrogen.

The Periodic Table is based on today's atomic theory. It provides the basic information about atomic structure and behavior - if you know how to read it!