Chapter 1
Exploring Life Science
I. Science – From Latin “scire” means to know
A. Theory
1. Most logical explanation of events
2. Powerful, time-tested concept
B. Law
1. Summerizes observed experimental facts
2. Can be changed through future observations and experiments
C. Branches fo life science
1. Zoology – study of animals
2. Botany – study of plants
3. Ecology – study of relationships betweem organisms and environments
4. Microbiology – study of microorganisms
II. Scientific method
A. Stating the problem
B. Gathering information on the problem
C. Forming a hypothesis
D. Performing experiments to test the hypothesis
E. Recording and analyzing data
F. Stating a conclusion
G. Repeating the work
III. Scientific measurements
A. Metric system
1. Universally used
2. System based on ten (decimal system)
B. Length
1. Basic unit of length is a meter
2. Slightly longer than a yard
C. Volume
1. Basic unit of volume is a liter
2. Slightly larger than a quart
D. Mass
1. Basic unit of mass is a kilogram
2. Measure of the amount of matter in an object
D. Weight
1. Basic unit of weight is the newton
2. A measure of the force of attraction between objects due to gravity
F. Density
1. The measurement of how much mass is contained in a given volume of an
object
2. Density = mass
volume
G. Temperature
1. Measured in degrees Celsius (C)
2. 0C = freezing point
3. 100C = boiling point
H. Dimensional analysis
1. Skill of converting one unit to another
2. Conversion factor
IV. Tools of scientist
A. Microscopes
1. Compound light microscope
2. Electron microscope
B. X-rays
1. Pass easily through skin and muscle
2. Blocked by dense material
C. CAT scan (Computerized Axial Tomography)
1. Gives cross-sectional pictures of object
2. Computer analyzes, combines and constructs one picture
D. MRI (Magentic Resonance Imaging)
1. Uses magnetism and radio waves to produce images
2. Able to study structure and function of body cells
E. Lasers
1. Produces a narrow, intense beam of light
2. May be used as a kind of scalpel
F. Computers
1. Electronic devices that collect, analyze, display and store data
2. Help to diagnose diseases
3. Prescribe treatments
V. Safety in the laboratory
A. Follow all safety procedures
1. Follow teacher’s directions
2. Follow directions stated in textbook exactly as stated
3. Learn meaning of safety symbols
4. Learn all safety precautions
B. Learn to protect yourself and fellow workers