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Chapter 3. Biological tools and Instrumentation. Taxonomic (Dichotomous) Key. 1a. Is the organism unicellular -go to step 2 1b. Is the organism multicellular -go to step 3 2a. Is the organism prokaryotic -kingdom Monera
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Chapter 3 Biological tools and Instrumentation
Taxonomic (Dichotomous) Key 1a. Is the organism unicellular -go to step 2 1b. Is the organism multicellular -go to step 3 2a. Is the organism prokaryotic -kingdom Monera 2b. Is the organism eukaryotic -Kingdom Protista
Scientific Method • An systematic approach to problems solving: 1. Defining the problem “ By doing Background Research” 2. Formulating a hypothesis 3. Testing the hypothesis 4. Recording observations 5. State a conclusion
Three types of Experiments • ****Controlled Experiments**** • Trial and Error • Open Ended
Defining the problem “By doing Background Research” • Hypothesis – • Experimentation 1. Control group (no change) 2. Experimental group (make change) control = variable = *State a conclusion
Defining the problem • Hypothesis –a possible explanation for events. • Experimentation (Testing the hypothesis) 1. Control group (no change) a source for comparison 2. Experimental group (contains 2 variables) *Independent Variable (Manipulated) *Dependent Variable (responding) #’s • State a conclusion
Theory- explanation supported by experimental evidence. • Scientific Law- is a statement that describes some aspect of a phenomena that is always true.
Microscopes • Simple Microscopes • Dissecting microscope • Compound Microscope • Phase Contrast Microscope • Electron Microscope • SEM • TEM
Instrumentation A. Simple microscope - magnifying glass 1 –uses 1 lens B. Compound light microscope 1- uses two lenses a) ocular (eyepiece) 10x b) objective - low power, 10x - high power, 40x
Compound Light Microscope • Magnifies 50x to 500x the original size • Used to look at the whole cell and organelles like the nucleus and chloroplast
Adjustments: • Coarse adjustment – used to focus under low power • Fine adjustment – used to focus under high power ONLY • Used to “fine tune” the image
Total Magnification: Magnifications: ocular = 10x low power objective = 10x high power objective = 40x Formula: ocular x objective = total magnification High power magnification is? 10 x 40 = 400x
Imagery: • When placing a slide under the objective lens, the image appears: -magnified -upside down -inverted (backwards). Ex: e F
e F F e Imagery:(as seen under low power)
Imagery:Field of View (fov) What is the size of the “F”? F F Scanner fov = 4000 um Low fov=2000 um
F Imagery:Field of View (fov) 4000 um
Electron Microscopes • Advanced microscope magnifies 250,000x the original size • Allows for detailed observation of smallorganelleswithin the cell. • Like the mitochondria and lysosomes.
Dissecting Microscope • Gives the viewer a 3-D image of the organism • Used in the dissection of small animals and plants • Low magnification • 1-10x
Separation Techniques Centrifuge Chromatography Gel electrophoresis Dialysis Tubing Dissection and micro dissection instruments Stains Indicators System International Other Biological Tools
Centrifuge:Separates of solutions based on each parts density Chromatography: Separates Solute from Solvent Electrophoresis:separates macromolecules-either nucleic acids or proteins-on the basis of size, electric charge, and other physical properties Dialysis Tubing Separation Techniques
Centrifuge • Separates of solutions based on each parts density
Electrophoresis Opposite charges at each side causing sample to move • Smaller DNA fragments move faster and further
separates nucleic acids or proteins-on the basis of size, electric charge, and other physical properties Electrophoresis:
Chromatography Rf= • Separates Solute from Solvent Distance traveled by the solute (ink) Distance traveled by the solvent (liquid)
Dissection Instruments • Tools used to perform dissection of Tissues/ organisms • Dissecting scope sometimes used
Micro dissection Instruments • Tools used to perform dissection of individual cells or the removal of cell organelles. • Most commonly used with the Electron microscope (greatest magnification).
Staining Techniques • The use of solutions to make it more possible for an observer to see structures of a cell easier under a microscope 1. Iodine- used primarily to stain nucleus of animal cell. 2. Methylene blue- used primarily to view chloroplasts and the cell wall of a plant cell.
Indicators • Designed to detect specific materials INDICATORS DETECTS • Iodine/ Lugols solution starch • Benedicts solution Glucose • Biuret solution proteins • Bromomethyl blue carbon dioxide and Lime water • Litmus paper acids or bases
SI: System International, The Metric System • The most common system of measurement used by scientists is the metric system. The metric system is based on the unit 10. (Based on multiples of ten) The metric system has many basic units for its’ measurements. (Length = is a meter, etc.)
SI: System International, The Metric System • Think of the basic units as Suffixes. *Meter, Gram. Second, Liter, Degree Celsius, • Think of the abbreviations as prefixes: • Kilo =1000 • Centi = 100th • Milli = 1000th