1. Intro to Science
Sept 2011
Biology 112

2. The Goals of Science Deals only with the Natural World
The supernatural is outside the realm of science

3. The Goals of Science
Collect & Organize Data

4. Goals of Science
3. Propose Explanations that can be tested

5. In Summary…..
SCIENCE is a BODY of KNOWLEDGE that EXPLAINS the NATURAL World.

6. Science Begins with Observation – How are your Skills?

7. OBSERVATION Quantitative – a quantity/number or measure
Qualitative – a quality/characteristic; description

9. Inference A logical interpretation based on prior knowledge
Examples of Inferences?
What can be the problem with inferences?

10. Hypothesis
A proposed explanation; must be TESTABLE; written in an “If….then” format
If I give my dog Purina dog food for a month, then he will not shed as much.
If I use miracle grow then my plants will produce more tomatoes.
If I use the drug Avapro for a week then my blood pressure will be lower

11. Scientific Inquiry~ inquisitive thinker’s!!!
Scientists make observations, ask questions and then try to answer them through research and experimentation.

12. Narrowing in on Science
BIOLOGY – One Branch of Science
Study of LIVING things 

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A Few Branches of Biology:
Zoologists
Botanists
Paleontologists
Cell Biologists
Geneticists
Microbiologists
Ecologists
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14. Biology is very broad (Remember it is the study of LIVING things…and there are LOTS of living things!!!!!) Terminology rich; very descriptive and has it’s own language~ – Handout #1 – Give it a try 

15. Answers: Learning the Language
Hydrology – study of water
Cytology - study of structure & function of cells
Protozoa – first animal
Epidermis – above skin
Spermatogenesis – beginning sperm
Cytoskeleton – cell skeleton
Abiotic – not living
Dermatitis – skin disease / inflammation
Hypodermic – below the skin
Hemophilia – blood like

16. Answers: Learning the Language
Endocytosis – internal cell
Insecticide – killer of insects
Anaerobic – not needing oxygen
Bilateral – two, twice, double sided, both sides
Endotherm – internal heat
Subspecies – species below
Arthropod – joint footed
Micrometer - small measurement
Hypothermia – below heat
Morphology – study of form

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1-2 How Scientists Work
Scientists make educated guesses about how things work the way they do. These are called HYPOTHESIS.
How do scientists test hypotheses?
A hypothesis should be tested by an experiment in which only one variable is changed at a time.
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18. Scientific Method Summary
Ask questions, make observations
Gather information
Form a hypothesis (educated guess)
Set up a controlled experiment
Manipulated variable - the variable that is deliberately changed (aka independent variable) Responding variable is variable that is observed (aka dependent variable)
5)Record and analyze results
6)Draw a conclusion
7)Repeat & share findings

19. Scientific Method – Step 1: Ask Questions/Make Observations:
2300 years ago people thought that some “special force” brought some things into being from nonliving material
Ex:
Beetles just “appeared” on cow dung
Mice were “found” on grain
Maggots “showed up” on meat
Good thing we don’t’ just rely on observations!!!

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The idea that living things arise from non-living matter is called:
spontaneous generation OR abiogenesis.
In Aristotle’s time, people hypothesized that maggots spontaneously appeared on meat.
FRANCESCO REDI – BEGAN CHALLENGING ARISTOTLE BY ASKING QUESTIONS and Following the steps of the scientific method!!
In 1668, Redi proposed a different hypothesis: that maggots came from eggs that flies laid on meat.
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Redi’s Experiment
Uncovered jars
Covered jars
Controlled Variables:
jars, type of meat,
Location, temperature,
time
In a controlled experiment, only one variable is tested at a time. Redi designed an experiment to determine what caused the sudden appearance of maggots. In his experiment, the manipulated variable was the presence or absence of the gauze covering. The results of this experiment helped disprove the hypothesis of spontaneous generation.
What do you think are the manipulated and responding variables in this experiment??
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22. John Needham – mid 1700’s – SG is BACK!???
English Scientist who tried to attack Redi’s work.
He heated a flask of gravy for a short time and corked the flask and microorganisms appeared.
He believed that the little “animalcules” must have come from the gravy!

23. Repeating Investigations – TRIALS!!!
Spallanzani's Test of Redi's Findings 
Gravy is boiled.
Gravy is boiled.
Spallanzani’s experiment showed that microorganisms will not grow in boiled gravy that has been sealed but will grow in boiled gravy that is left open to the air. Interpreting Graphics What variable was controlled in this experiment?
Which variables are controlled??
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24. Spallanzani – Disproving SG!
Flask is open.
Flask is sealed.
Is the flask the manipulated or responding variable??
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Gravy is teeming with microorganisms.
Gravy is free of microorganisms.
Helped prove the theory of BIOGENESIS!!!! Living things come from other living things!
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Pasteur's Test of Spontaneous Generation
Louis Pasteur conclusively disproved the hypothesis of spontaneous generation.
Pasteur showed that all living things come from other living things.
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Pasteur’s Experiment
Broth is free of microorganisms for a year.
Curved neck is removed.
Broth is teeming with microorganisms.
Pasteur’s experiment showed that boiled broth would remain free of microorganisms even if air was allowed in, as long as dust and other particles were kept out.
Broth is boiled
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The Impact of Pasteur’s Work
He began to uncover the nature of infectious diseases, showing that they were the result of microorganisms.
Pasteurization of dairy products 
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29. SCIENTIST SUMMARY:
PRO SG: Aristotle, Needham ANTI SG: Redi, Spallanzani, Pasteur

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1-3 Studying Life
Photo Credit: © Andrew Syred/Science Photo Library/Photo Researchers, Inc.
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So…If Biology is the study of living things….
What makes something living?
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Living things share the following characteristics:
*REFERENCE PAGE – pages 16/17 of student text!!
1. Made of cells
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33. 2. Reproduction
Reproduction

34. 3. Universal genetic code

35. 4. Grow & Develop

36. 5. obtain and use materials and energy

37. 6. respond to stimuli

38. 7. Maintain a stable internal environment (called homeostasis/equilibrium)

39. 8. change over time

40. Make a table with the heading “CAR”
Living NonLiving

41. Microscopes
Anton van Leeuwenhoek ( ) was responsible for the first “microscope” as we know them today
Due to his knowledge of lenses he was able to construct a piece of equipment that made things appear closer and larger.

42. Microscopy and Measurement
Microscopes – produce an enlarged image of an object
Used to study organisms, cells, and cell parts
Increase in apparent size is called magnification
The ability to show details clearly is called resolution
Microscopes vary in both magnification and resolution

43. Compound Light Microscope (2 lens-microscope)
Uses light passing through a medium of liquid to view a specimen
Uses generally a 10X ocular lens in addition to a 4x, 10x, 40x objective lens
Magnification = ocular x objective
Limited in it’s magnification
Used to view living and dead specimens

44. Magnification Example:
Using the compound microscope in your classroom, you are asked to view a piece of hair under the medium power objective. What is the total Magnification of the hair being viewed?
What exactly does that mean?

45. Types of MICROSCOPES Light vs. Electron
Smallest size seen with the Naked Eye is….
0.2mm = one ridge on your finger print (resolution OR resolving power)
Light Microscopes can view mm
Electron Microscopes can view mm (0.2 nm)

46. Parts of the Compound Microscope – Fill in your sheet as we go!!

47. Parts of the Compound Microscope
Stage – supports the slide. The central opening in the stage allows light to pass through.
Clips – Keep the slide in position
Diaphragm – Regulates the amount of light reaching the object being viewed
Revolving Nosepiece – changes the objective lenses
Ocular Lens – Viewing (10X)/Eyepiece
Course Adjustment – Moves the body tube up or down so you can get the specimen in focus. It is used with the low power objective only!
Fine Adjustment – Used with med or high power to get the specimen in sharper focus
Condenser Lens – Directs light to the object or specimen.

48. Microscope Use

49. Focusing a Microscope
Always start with the low power objective (4X). Odds are, you will be able to see something on this setting. Use the Coarse Knob to focus.
Once you've focused on low power, switch to Med Power (10X). Use the Coarse Knob to refocus. Again, if you haven't focused on this level, you will not be able to move to the next level.
Now switch to High Power. (40X)
If the specimen is too light or too dark, try adjusting the diaphragm.

50. Making a Wet Mount
Gather a thin slice/piece of whatever your specimen is. your specimen is too thick, then the coverslip will wobble on top of the sample like a see-saw, and you will not be able to view it under High Power.
Place ONE drop of water/dye directly over the specimen. If you put too much water, then the coverslip will float on top of the water, making it hard to draw the specimen, because they might actually float away. (Plus too much water is messy)
Place the coverslip at a 45 degree angle (approximately) with one edge touching the water drop and then gently let go. Performed correctly the coverslip will perfectly fall over the specimen

51. Finished with your Microscope?
1. Store microscopes with the scanning objective (4X) in place. 2. Wrap cords and cover microscopes. 3. Wash slides/slips in the sinks and dry them, placing them back in the slide boxes to be used later. 4. Carry with 2 hands (arm/base) 5. Put back in the correct location

52. Transmission Electron Microscope
Uses electrons instead of light
Capable of over 1,000,000X magnification
Specimens that contain many layers of cells, such as blood vessels, cannot be examined
A thick specimen would absorb all the electrons and produce a blackened image
Only view thin sections encased in plastic
Size of Specimen
1 to 5 nm in size

53. TEM cont..

54. Smooth Muscle Cells

55. Negative Stain Rota Virus

56. Negative Stain Corona Virus (Animal Virus)

57. Scanning Electron Microscope (SEM)
Produces a 3-D image
View up to 300,000X CHANGE
Takes “pictures” of surfaces
Specimens are usually preserved, coated in a metal, dehydrated…so specimen being viewed is non-living.
Add in:
Size of Specimen
1 to 5 nm in size

58. Scanning Electron Microscope

59. SEM cont…

60. Guess?

61. Guess??

62. Guess??

63. Guess??

64. TYPES OF MICROSCOPE COMPOUND LIGHT TRANSMISSION ELECTRON
SCANNING ELECTRON
HOW IMAGE IS FORMED
LIGHT WAVES
ELECTRON BEAM
MAGNIFICATION
1000 X (2000X) X X
THICKNESS (IMAGE)
WHOLE OR PART
THIN
3-D
COVERED IN GOLD
SIZE
0.2 um (200 nm)
10 nm – 100 nm
1 nm – 5 nm
ALIVE OR DEAD
BOTH
DEAD
MEDIUM
LIQUID
VACUUM
(STAINING)

65. Rules for Biological Diagrams
See handout (rules/practice assessment)

66. Figure 1 – Moss Cross-section

67. Biological Diagrams - Lab #1
Following all steps for biological diagrams complete the following:
(Do two drawings on one page of plain paper)
Obtain a sample from the front and draw the specimen in the container (do not draw the bottle)