What is Biology ? The study of Living Things Bio = life logy = knowledge (study of)

How to Study Biology ? So many new words ! – know some common prefix and suffix – eg. photosynthesis photo = light synthesis = to combine together to combine some elements together by using the energy from sunlight

Characteristics of Life Living things… – Are made up of units called cells – Reproduce – Are based on a universal genetic code – Grow and develop – Obtain and use materials and energy – Respond to their environment – Maintain a stable internal environment – Change over time

Levels of Organization and This Semesters Progression We will be moving through organization from the smallest to the largest! Molecules Cells Groups of cells Organisms Population Community Ecosystem Biosphere

Molecules Cells Groups of Cells

Organism Population Community

Ecosystem Biosphere

The Scientific Method

Defining Science Pure Science – research that adds to the body of scientific knowledge – has no practical use Applied Science (Technology) – the practical application of scientific knowledge

A. Defining Science PURE human genetics polymer science atomic theory study of the human ear APPLIED DNA fingerprinting Lycra ® spandex nuclear weapons hearing aids

The Scientific Method An organized way to solve a problem through experimentation & observation.

The 6 Steps of the Scientific Method

1. State the Problem Form a question about a specific event or reaction EX: Mouthwash kills bacteria. Which brand works best?

2. Collect Information Research the problem EX: Read the labels of 3 common brands of mouthwash and see which has the most antiseptic (germ-killing) ingredients.

3. Form a hypothesis Make an educated guess based on your research. EX: If Listerine has more antiseptic ingredients than Scope or Wal-Mart brand, then it will kill more bacteria. A hypothesis can be recognized by an “if, then” statement.

4. Design an Experiment Devise a way to test your hypothesis. Create aCONTROLLEDexperiment.

A controlled experiment MUST have 2 groups. CONTROL GROUP: all conditions remain the same EXPERIMENTAL GROUP: only the condition that you are testing for is changed ONLY 1 condition is changed!

Establish the variables for your experiment. INDEPENDENT VARIABLE: the variable that is changed, manipulated (X axis for graphing) DEPENDENT VARIABLE: the change caused by the manipulation of the independent variable (Y axis for graphing)

Mouthwash Experiment Petri dish Bacteria grown from swab Control Group -no mouthwash Experimental Group Listerine Scope Wal-Mart brand

Mouthwash Experiment INDEPENDENT VARIABLE: DEPENDENT VARIABLE: Type of Mouthwash Amount of bacteria killed

5. Collect & Analyze Data Run the experiment & document the data

2 Types of Data QUANTITATIVE: numerical data, deals with specific quantities, usually in the form of a graph or chart QUALITATIVE: descriptive data, describes how something looks, smells, sounds, or feels; deals with qualities

QUALITATIVE EX: The control group and the Wal-Mart brand have a strong smell; the Listerine & Scope don’t smell as bad. QUANITATIVE EX: Area of Inhibition for Mouthwash Brands ControlListerineScopeWal-Mart 5 min0 mm3 mm2 mm1 mm 10 min0 mm4 mm3 mm 15 min0 mm6 mm5 mm4 mm 20 min0 mm8 mm6 mm4 mm

6. Draw Conclusions Determine from the data collected if the hypothesis was correct or incorrect EX: Listerine did kill more bacteria than the other brands because it had more antiseptic ingredients.

Data Presentation Graphing Types of graphs

A. Types of Graphs Line Graph – shows the relationship between 2 variables – Continuous Dependent Variable Independent Variable

A. Types of Graphs Bar Graph – shows information collected by counting – Categorical

A. Types of Graphs Pie Graph – shows distribution of parts within a whole quantity – Percentages