The Science of Biology

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The Science of Biology

• Chapter 1

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What is Science

• The Goal of Science to investigate and
  understand the natural world.
• Explain events in the natural world
• Use those explanations to make predictions
• Science is an organized way to explain the world
  around us.
• Scientists make observations to create data.
  There are two types of data
• Quantitative in numbers able to be measured
• Qualitative Descriptive or appearance
• Inferences are logical interpretations based on
  prior knowledge.

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Science and You

• Scientists analyize data and make a Hypothesis.
• A hypothesis is based on prior knowledge
• State a hypothesis so it may be tested by a
  controlled experiment.
• Science is an ongoing process. There are no
  absolute truths
• Science will provide information with moral and
  ethical ramifications.

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Scientific Method

• There are 6 steps to the Scientific Method.
• Observe and ask a question
• Form a hypothesis
• Set up a controlled experiment
• Record and analyze result data
• Draw a conclusion
• Replicate and Report work (results should always
  be the same)

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A Controlled Experiment

• Factors in an experiment that change are the
  variables. Test only one variable.
• The experiment is setup in duplicate
• The control setup, where nothing is changed
• The experimental setup, where 1 variable is
  changed. This is the manipulated variable.
• The variable that reacts to the manipulated
  variable is the responding variable

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Scientific Method A Case Study

• In 1668 Francesco Redi challenged the idea of
  spontaneous generation.
• He created a controlled experiment to disprove
  spontaneous generation.
• He published his results and they were tested by
  John Needham in the mid 1700s
• Anton van Leeuwenhoek using lenses discovered
  animalcules in water.
• Needham developed an experiment to prove that
  animalcules could arise from gravy.

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• Needhams experiment said life could be created
  in the right conditions. He proved spontaneous
  generation.
• Spallanzani wanted to improve on Needhams
  experiment and set it up in duplicate. He
  disproved Needham.
• Scientists argued that air was needed for life.
• Pasteur set up a simple experiment which finally
  proved spontaneous generation was wrong.
• Know all of the details in each experiment.

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Theories in Science

• If an experiment is not possible a field study of
  observations may work.
• Ethical issues arise in certain experiments.
• A theory is a well supported hypothesis.
• A theory unifies a broad range of observations
  is well tested supported.
• Theories may be revised or replaced.

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Characteristics of Living Things

• Living things are made up of units called cells.
• Living things reproduce. (two types)
• Living things are based on a universal genetic
  code.
• Living things grow and develop.
• Living things obtain and use materials and
  energy. (metabolism)
• Living things respond to their environment.
• Living things maintain a stable internal
  environment. (Homeostasis)
• Taken as a group living things change over time.

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Levels of Biology

• Molecular- atoms combine into molecules
• Cellular- studying individual cells
• Tissue- Studying groups of cells function
• Organism- Structure function of organisms
• Populations- group of organisms in one area
• Community- populations living together in a
  defined area
• Ecosystem- communities and its nonliving
  surroundings
• Biosphere- The part of Earth containing all
  ecosystems.

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Branches of Biology Future Careers

• Anatomy- study of internal structure
• Bacteriology- study of microscopic bacteria
• Botany- study of plants
• Cytology- study of structure and function of
  cells
• Ecology- study of environmental issues
• Embyrology- study of early development of
  organisms
• Entomology- study of insects
• Eugenics- branch of genetics dealing with humans
• Herpetology- study of reptiles
• Histology- study of tissues
• Ichthyology- study of fish

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Branches of Biology

• Morphology- Study of total structure of organisms
• Mycology- study of fungi
• Ornithology- study of birds
• Paleontology- study of past geological periods
• Parasitology- study of parasites
• Pathology- study of disease
• Physiology- study of function of organisms
• Protozoology- study of protozoan
• Taxonomy- naming, grouping, and classifying
  organisms
• Virology- study of viruses
• Zoology- study of animals

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The Metric System

• SI units are on a scale of ten and prefixes tell
  you the value of a unit.
• Micro 1/1,000,000 .000001 one millionth
• Milli 1/1000 .001 one
  thousandth
• Centi 1/100 .01 one
  hundredth
• Deci 1/10 .1 one
  tenth
• Deka 10/1 10.0
  ten
• Hecto 100/1 100.0 one hundred
• Kilo 1000/1 1000.0 one thousand
• Standards are the meter, liter, kilogram

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Microscopes Tools of a Biologist

• Compound Light Microscope- most common,
  reasonable priced, easiest to operate microscope
  uses two lenses.
• Limits to the CLM, resolution of 0.2 micrometers
  or 1,000,000th of a meter
• CLM need stained specimens or use of phase
  contrast
• Three magnifications, 4-red, 10-yellow, 40 -blue
  all x10
• Stereoscopic Microscope- used for large
  specimens
• Low magnification 15X or 30X
• Three dimensional
• Easy to operate
• May see entire specimen

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Types of Electron Microscopes

• Transmission Electron Microscope (TEM)
• uses florescent plate and coats specimen in metal
  dust
• Scanning Electron Microscope (SEM)
• uses intense spot of electrons scanned across
  specimen
• may show three-dimensional images
• Limitations of electron microscopes
• placed in a vacuum (dead)
• TEM treats with chemicals and must be cut thin

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Worksheet

• Eyepiece

• Body Tube

• Nosepiece

• Arm

Objectives

• Stage Clips

Aperture

• Stage Stop

• Stage

• Coarse Adjustment knob

• Diaphragm

• Light Source

• Fine Focus Adjustment

Base
Power switch
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Lab Techniques

• Safety is always first. Read labels and follow
  proper lab techniques.
• Never taste or directly smell a substance.
• Cell Cultures- growing many cells from one sample
  cell
• Cell Fractionation- Breaking a cell to study only
  one part of the cell
• Centrifugation- Spinning material to separate it
  by mass.