Introduction to Biology

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Introduction to Biology

• Studying Lifes Diversity and Intricate Processes

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Biological Inquiry

• Bio of living things
• What Are the Characteristics of Living Things?
• How Do Biologists Study Living Things?

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What is Life?

• A living thing is an
• organized
• genetic unit capable of
• metabolism
• reproduction and
• evolution

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Characteristics of Living Things

• Organisms are composed of highly organized cells.
• Cell smallest unit of life
• Organic molecules carbon-containing
  building blocks of life

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Organizational Hierarchy of Life
biosphere
inhabitable regions of earth
ecosystem
coral reef (living nonliving)
community
coral reef populations
population
school of fish
organism
fish
organ system
nervous system
organ
brain
tissue
nervous tissue
cell
neuron
organelle
nucleus
macromolecule
DNA
molecule
nucleotide
atom
nitrogen
sub-atomic particles
protons, neutrons, electrons
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Characteristics of Living Things

• The molecule of heredity DNA
  deoxyribonucleic acid

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Characteristics of Living Things

• Living things acquire and use materials and
  energy
• Energy ability to do work
• Metabolism sum of chemical reactions in an
  organism

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Characteristics of Living Organisms

• Living things maintain homeostasis a
  relatively stable internal condition

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Characteristics of Living Things
Nuclear division retaining the original
chromosome number

• Reproduction Allows Life to Continue

Nuclear division reducing the chromosome number,
leading to sperm or eggs
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Characteristics of Living Things

• Living things grow and develop.
• Growth increase in size
• Development change in characteristics

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Characteristics of Living Things

• Reproduction Provides the Variation for
  Evolutionary Change
• Evolution Change in genetic composition of a
  population over time
• Adaptation characteristic that promotes
  survival and reproduction

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Summarizing the Characteristics of Living Things

• A living thing
• is composed of highly organized cells
• is controlled by the genetic material DNA
• is capable of metabolism and maintaining
  homeostasis
• reproduces, grows and develops
• belongs to a population that changes over time by
  evolution

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How Do Biologists Study Living Things?

• Hypothesis-Prediction Approach
• Make Observations objective notations of a
  phenomenon
• Ask Questions
• Formulate Hypotheses
• tentative answers to questions
• Make Predictions based on Hypotheses
• Test Predictions by Conducting Experiments or
  Making Further Observations

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How Do Biologists Study Living Things?

• Biology 21 Definition
• An Hypothesis will have
• Two measurable variables
• Precise relationship between them (relationship
  prediction in H-P model)

The relationship between DNA content and length
of the cell cycle is a direct proportion.
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How Do Biologists Study Living Things?

• Testing hypotheses
• Controlled Experiment
• test designed to determine the effect of one
  factor while keeping all other factors constant
• experimental sample treated to test for effect
  of the factor being studied
• control sample treated like experimental in all
  ways EXCEPT for the factor being studied
• Comparative Method
• collection of data to determine whether patterns
  predicted by specific hypotheses can be observed

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Use of a Controlled Experiment
Increasing dose of almonds on subjects with
hyperlipidemia. Full almond 73
grams/day Control whole wheat muffins (gt5
saturated fat) Half almond half dose almond
half dose muffins All supplements provided equal
amounts of energy in the diet. Jenkins, et al.,
2002, Circulation 1061327
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Use of Comparative Method
Evaluating women enrolled in the Nurses Health
Study for correlations between fat intake and
incidence of heart attack. Hu, et al., 1997, New
England Journal of Medicine, 3371491-1499.
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How Do Biologists Study Living Things?

• Supported Hypothesis
• Theory hypothesis supported by repeated testing
• Principle or Law theory that has been supported
  over a long period of time
• Cell Principle
• Principle of Evolution
• Principle of Emergent Properties
• new characteristics arise out of the organization
  of the components of a complex system (whole gt
  sum of the parts)