The Science of Biology Chapter 1 p 2-28 2009 1Biology 2009 Scientific Method

The Science of BiologyChapter 1 p 2-28

2009

1Biology 2009 Scientific Method

Terms:• Science - Asexual Reproduction• Observation - Homeostasis• Inference - Metabolism• Hypothesis - Biosphere• Controlled experiment - Scientific Method• Independent variable - Experimental group• Dependent variable• Control group• Control/ placebo• Data• theory• Bias• Biology• DNA• Stimulus• Sexual Reproduction

Biology 2009 Scientific Method 2

Term: Science

Derived from Latin word scientia which mean “knowledge”

Knowledge that has been gathered over time


What is Science- What are its Goals• Science is used as a way of “Knowing”• Used to make observations• Used to gather and analyze evidence• Scientific Studies collected over time• Deals with the natural world • Organized • Conclusions based on evidence- not beliefs• Used to provide explanations of events• Used to predict future event


Key Point

• Science is not a collection of unchanging beliefs about the world.

• Science is constantly changing- What you parents learned in HS may not be what you are learning today. What may be printed in your current text could be wrong this afternoon.

• It is important for you to be a critical thinker and continue to ask questions about the known and the unknown!!


Problem• You come home from school today and you

find that your lights are out- What do you do?


Scientific Method1. Observation- What you see

2. Inference- logical interpretation based on what some one might know, personal experiences

3. Hypothesis- educated guess that can be both testable and falsifiable, explanation of observations


Inference vs. Observation

1. The skin is red2. The strawberry is edible3. The skin is rough4. The skin is easily broken 5. There are no seeds inside the berry


Scientific Method Cont:

4. Design a Controlled Experimentkeep all but one variable the sameIs used to test a hypothesis and predictions a. Control Group- normal standard which biologists

compare the experimental group b. Experimental Group- what is being changed in

the experiment


Scientific Method cont:

Two types of Variables:1. Independent –what is changed, what

you are testing (Manipulated variable) (x-axis)

2. Dependent-what is measured, it changes in response to the independent (Responding variable) (y-axis)


Scientific Method

5. Collect and Analyzing DataThis is very important- collect data as it is – it is

what it is!! DO NOT fix your data to fit your hypothesis!!

Two Types:Quantitative- numbers, measurementsQualitative- can not be counted, survey,

observations


Scientific Method cont:

6. Drawing Conclusions: using the data to support or dispute original hypothesis

7. Possible Errors8. Revise Hypothesis/ experimental design9. Peer Review- evulations of ones work10. Theory- well-tested explanation that unifies

a broad range of observations and hypotheses that allow for scientist make accurate predications about new situations



Science and SocietyHow do these things influence science??Things that can change the way we think about

science:• Technology• Religion• Ethics and morality• Bias- personal rather than scientific


Use the Scientific Method to Solve the Problem

• Observe: grass length? Why do marsh grasses

grow to different heights in different places?


Based on your knowledge what factors could change the growth? Come up with a hypothesis.

Factors:

Hypothesis:

How could you test it: Control:Variables:




Analyze the Data

• Hypo:

• Independent:

• Dependent:


Analyze the Data

• Hypo:

• Independent:

• Dependent:


Analyze the Data

• Hypo:

• Independent:

• Dependent:


1.3 Biology- Study of LifeWhat is life? What makes something Living?Characteristics of living things1. Made of cells (Cell Theory)2. Made of DNA- universal genetic code3. Obtain and use materials and energy (metabolism)4. Grow and develop5. Reproduce (sexual & asexual)6. Respond to the environment (stimulus)7. Maintain stable internal environment- homeostasis8. Ability to change over time (Evolution)


Big Ideas1. Cellular basis of life2. Information and heredity3. Matter and energy4. Growth, development and reproduction5. Homeostasis6. Evolution7. Structure and function8. Unity and diversity of life9. Interdependence in nature10. Ways of knowing


Scientific Measurement• Use metric system (CPE review)


Tools and Techniques

Light Microscopes (compound light micro)- Shines light through a specimen and has two

lenses to magnify and imageParts- 1. Eyepiece or Ocular lens- magnifies the images

(10X)2. Objective lens- enlarges images 3. Stage- supports a slide4. Light source- provides light


Magnification and Resolution

Magnification- is the increase of an object’s apparent size.

Power of magnification- objective lens X the ocular lens ( 100x X 10x = 1000x)

Resolution- the pose to show details (clarity)


Electron Microscopes

1. Scanning electron microscope (SEM)-Uses beams of electrons (100,000 times)3-dimensional

http://www.mos.org/sln/sem/sem.html2. Transmission electron microscope (TEM)-

(200,000 times)detailed

http://www.sciencephoto.com/html_tech_archive/transm.html


http://www.mos.org/sln/sem/sem.html




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The Science of Biology Chapter 1 p 2-28 2009 1Biology 2009 Scientific Method