The%20Nature%20of%20Life%20Chapter%201-3%20

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The Nature of LifeChapter 1-3 1-4

• The Science of Biology

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Studying Life

• Biology is the study of living things
• Bio life ology study

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Studying LifeCharacteristics of Living Things

• Nonliving things share some characteristics with
  living things, but not all
• 5 characteristics of living things
• Made up of cells
• Reproduce
• Based on genetic code
• Metabolism
• Homeostasis
• To be considered living, an object MUST have ALL
  5 characteristics

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Studying LifeCharacteristics of Living Things

• 1. Made up of cells
• Smallest unit of life
• Enclosed by a barrier that separates cell from
  surroundings-membrane
• Unicellular- one celled like bacteria
• Multicellular- many celled like animals and
  plants

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Studying LifeCharacteristics of Living Things

• 2. Reproduction
• All organisms can produce new organisms
• Passing on of genetic information
• Two types of reproduction
• Sexual
• Asexual

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Studying LifeCharacteristics of Living
ThingsReproduction

• Sexual reproduction- two cells (egg and sperm)
  from different parents unite to form the 1st cell
  of the new organism
• Humans, dogs, apes
• Flowers

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Studying LifeCharacteristics of Living
ThingsReproduction

• Asexual reproduction- new organism has only
  single parent and buds off that parent
• Hydra and some
• unusual plants

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Studying LifeCharacteristics of Living Things

• 3. Based on genetic code
• DNA or RNA
• Changes (evolves) with time
• Housed in body cells/passed in sex cells
• Sexual reproduction -offspring have traits from
  BOTH their parents
• Asexual reproduction -offspring have exact same
  traits as SINGLE parent

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Studying LifeCharacteristics of Living Things

• 4. Metabolism- process of building up or breaking
  down materials
• i.e. bone growth and digestion
• Use energy and constant supply of materials
• Produce waste products

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Studying LifeCharacteristics of Living Things

• 5. Homeostasis- maintain stable internal
  conditions--body temp
• Can respond to the environment
• Plant-leans to get light
• Animal
• Body temperature
• Blood vessel dilation
• Sweating
• Shivering
• Blood pH
• Homeostasis Animation

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Studying LifeLevels of Organization
Biosphere
Ecosystem
Community
Population
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Studying LifeLevels of Organization
Organism
Groups of Cells
Nerve cell
Cells
DNA
Water
Molecules
Which of these levels do not contain living
things?
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Studying LifeScientist Specialization

• Biologists
• Ecologists
• Population biologists
• Zoologists
• Cellular biologists
• Molecular biologists

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Studying LifeScientists Tools

• Common measurement system
• Metric system or (SI)- a measurement system used
  worldwide by scientists based on multiples of 10
• Mass-grams (g)
• Volume-liters (L)
• Distance-meters (m)
• Temperature- Celsius (oC)

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Studying LifeScientists Tools

• Different types of microscopes
• Light microscopes-magnifies images by focusing
  light on them
• Most commonly used
• Compound light microscopes- have two lenses
• Stains may be added to make objects more visible
• Electron microscopes- magnifies images by
  focusing a beam of electrons on them

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Studying LifeScientists ToolsMicroscopes

• Electron microscopes
• Produce magnified images by focusing beams of
  electrons on them
• Can produce images 1000Xs more detailed than
  light microscopes
• Two types
• TEM (transmission electron microscope)
• SEM (scanning electron microscope)

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SEM photoWhat is this?
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Foot of a Housefly