Chapter 1 (Campbell's Biology in Focus)

What is biology?

• The scientific study of life poses questions about the living world and seeks answers through scientific inquiry and central activities of biology
  • ==A biosphere== consists of all life on Earth and all the places where life exists
  • ==An ecosystem== consists of all the living things in a particular area along with the non-living components
  • ==A biological community== is the array of organisms inhabiting a particular ecosystem
  • ==A population== consists of all the individuals of a species living within the bounds of a specified area
  • Individual living things are called organisms

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The two types of cells

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• A ==eukaryotic cell== contains membrane-enclosed organelles. Some organelles, such as the DNA-contained nucleus, are found in the cells of all eukaryotes; other organelles are specific to particular cell types
• ==Prokaryotic cells== lack a nuclear or other membrane-enclosed organelles(generally smaller than eukaryotic cells)

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Evolution

• Evolution is the scientific explanation for the unity and diversity of organisms

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The Three Domains of Life

• Prokaryotic organisms - these are single-celled organisms
  • ==Bacteria==
  • ==Archae==
• Eukarya - all the eukaryotes are grouped into this domain
  • This domain contains three kingdoms of multicellular eukaryotes
  • Plantae
  • Fungi
  • Animalia

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Charles Darwin and the Theory of Natural Selection

• Species accumulate differences from their ancestors as they adapt to different environments over time.
• “Natural selection” is a primary cause of the descent with modification
  • ==Natural selection== is when the natural environment consistently “selects” certain traits among naturally occurring variant traits in the population

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Scientists and the study of nature

• ==An inquiry== is the search for information and explanations of natural phenomena
• ==Data== is recorded observations
• ==A hypothesis== is an explanation, based on observations and assumptions, that leads to testable predictions
• ==An experiment== is a scientific test, often carried out under controlled conditions

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