The Science of Life

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Chapter 1

• The Science of Life

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The Study of Life

• Biology the study of living things
• Some Fields of Biology entomology (insects)
• parasitology
  (parasites)
• microbiology
  (bacteria)
• ornithology
  (birds)
• herpetology
  (reptiles)

3
Six Major Themes of Biology

• Cell structure and function
• Stability and homeostasis
• Reproduction and inheritance
• Evolution
• Interdependence of organisms
• Matter, energy, and organization

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Cell Structure and Function

• Cells are the basic unit of life
• All organisms are made of and develop from cells

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Unicellular Organisms

• Organisms composed of only one cell
• Examples bacteria and protists

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Multicellular organisms

• Organisms composed of more than one cell
• May be highly complex
• Examples plants and animals

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Facts about cells

• Cells are highly organized
• Contain specialized structures
• There are many different kinds of cells
• Contain genetic material

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Differentiation

• In multicellular organisms, cells become
  different as they grow and develop
• After fertilization, cells divide and will
  eventually become specialized

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Stability and Homeostasis

• Living things maintain stable internal conditions
• Examples body temperature, water content,
  electrolytes

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Reproduction and Inheritance

• Organisms transmit hereditary information to
  their offspring
• DNA (deoxyribonucleic acid)
• Gene a short segment of DNA that contains
  instructions for a single trait

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Sexual Reproduction

• Production of offspring from the combination of
  genetic material from two parent organisms
• Example
• sperm egg zygote

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Asexual Reproduction

• Doesnt require two different organisms
• One cell gives rise to two cells
• Example binary fission in bacteria and protists

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Evolution

• Evolution a genetic change in a population over
  a long period of time
• Natural selection organisms that have favorable
  traits will survive better and pass those traits
  on to their offspring

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Evolution by Natural Selection

• Driven by competition among individuals for
  resources
• Individuals that can survive will be able to mate
  
• Traits are inherited by offspring

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Interdependence of Organisms

• Ecology the study of the interactions of
  organisms and their environment
• Ecosystems environmental communities

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Fragile Environments

• All life is interconnected
• When one aspect of the environment is harmed, it
  will have a negative impact on the whole ecosystem

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Matter, Energy, and Organization

• Almost all energy on Earth comes from the sun
• Photosynthesis- plants capture energy from the
  sun use it to manufacture glucose

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Autotrophs

• Organisms that make their own food
• self-feeders
• Example plants

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Heterotrophs

• Organisms that must take in food to meet their
  energy needs
• other-feeders
• Examples rabbits, coyotes, bears

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Conclusion

• Biology is the study of life, ranging from the
  study of unicellular organisms to the study of
  global interactions among millions of organisms

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All forms of life deserve protection and respect