BIOLOGY AS A SCIENCE

CHAPTER 1

A. Process which produces a body of knowledge about nature

B. Sciences1. Physical Sciences

Chemistry Physics Earth and Space

2. Biological Sciences Zoology Botany Others

C. Technology is the application of scientific knowledge to real world problems

1-1 SCIENCE

D. Biology1. Defined

Bio - ology - The study of living things Organisms

2. Importance Food (production, preparation, spoilage) Pets Plants (house plants, yard, harmful plants) Child care Disease Pests Heredity

3. Careers Wellspan is the largest employer in the county

A. Observation1. Process of gathering information

Use our senses Tools extend our powers of observation

2. Facts are confirmed observations3. Data

Recorded observations Words, Numbers, Graphs, Sketches, Notes, Video,

Audio, Photographs

B. Interpretation1. Explanation of the facts2. Not always correct

1-2 SEARCH FOR KNOWLEDGE

INTERPRETATION

INTERPRETATION

A. Logical method of problem solvingB. No one set methodC. Basic Steps

1. PROBLEM2. RESEARCH3. HYPOTHESIS4. EXPERIMENT5. CONCLUSION

D. Subject to verification

1-3 THE SCIENTIFIC METHOD

A. Variables are factors that can affect the outcome of an experiment

1-4 CONTROLED EXPERIMENTS

EXAMPLE: Plant GrowthLIGHT KIND OF PLANT

TEMPERATURE NUMBER OF PLANTS

WATER SPACING

SOIL SIZE OF POT

FERTILZER OTHER PLANTS

B. Two groups1. CONTROL GROUP

Group under normal conditions All variables are controlled Group used for comparison

2. EXPERIMENTAL GROUP Group being tested All variables are controlled EXCEPT ONE Tells if the factor being tested actually affected the

outcome of the experiment

C. Groups must be large for valid results1. Excludes individual differences2. All variables are controlled

A. LAWSStatements about events that always

occur in nature1. Sir Isaac Newton – The Law of Gravity2. Does not explain why

B. THEORIESBest explanation science has to offer of why things occur in nature

1. Have held up over long periods of time2. Sir Charles Darwin – Theory of Evolution

C. Laws and Theories1. Subject to revisions2. Can be used to make predictions

1-5 LAWS and THEORIES

A. Compare sets of numerical dataB. Each number is a variableC. Types of variable

1. INDEPENDENT VARIABLE Placed on the X-AXIS of Graph Set by the person conducting the experiment

2. DEPENDENT VARIABLE Placed on the Y-AXIS of Graph Data collected from the experiment Depends on the independent variable

1-6 GRAPHS

GRAPH of LION GROWTH

1 2 3

20

40

60

80

100

MA

SS

(k

g)

Depend

ent

Vari

able

on Y

-A

XIS

V

ert

ical

TIME (yrs)Independent Variable on X-

AXIS Horizontal

□ =

10

kg

□ = 2 months

TITLE: Growth of Lions

Axis range depends on highest and lowest values of data Graphs do not need to start at zero Each block must equal the same amount Spread your data over the available space Connect points with a smooth line curve

A. The Microscope1. Tool used to study small objects (microscopic)2. Main Functions

Magnificationa. To enlargeb. E.g. 5X

Resolutiona. Sharpness (detail)b. Ability to define spacec. Limit of the eye is 0.1 mm

1-7 MICROSCOPES

B. Types of Microscopes1. Light Microscope

SIMPLE MICROSCOPEa. Uses one lensb. Magnifying Glass

COMPOUND MICROSCOPEa. Uses TWO lenses

b. Total Magnification

EYEPIECE (Ocular)

EYEPIECE

x OBJECTIVE

= TOTAL MAGNIFICATION

x =

x =

x =

OBJECTIVE (High and Low Power)

c. Field of View What you see The greater the magnification the less you see

d. Microscopic Measurement Micrometer (µm) 1000 µm = 1 mm Nanometer (nm) 1000 nm = 1 µm

20X 4X

2. Electron Microscopes TRANSMISSION ELECTRON MICROSCOPE (TEM)

a. Sends electrons through a specimenb. Magnifications of 200,000x plusc. Limit of light microscope is 2000x

SCANNING ELECTRON MICROSCOPE (SEM)a. Sends electrons across a specimenb. Magnifications of 100,000x but 3D

Major Limitation is not being able to view living thingsa. Can’t survive preparationb. Can’t exist in a vacuum