Biology: The Study of Life

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Biology The Study of Life

• Chapter one
• READ Chapter 1 by Friday!

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What is Life?

• What makes something Alive?

Is this alive?
Does it have any life characteristics?
What does it have in common with this?
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Alive? Agree, Disagree, Unsure

• List 8 characteristics you KNOW all living things
  must have
• Observe object 1 2
• Living or Non?
• Check off each of YOUR characteristics for each
  object

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Characteristics of Living ThingsThe Rules of the
Living Game

• 1. Made up of units called cells
• 2. Reproduce
• 3. Contain DNA
• 4. Grow and develop
• 5. Obtain and use materials and energy
• 6. Respond to the environment/stimulus
• 7. Homeostasis
• 8. Evolve

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1. Cells are Basic Units of Structure and Function

• Prokaryotic vs. eukaryotic
• P no nucleus or membrane-bound organelles
• E nucleated with membrane-bound organelles

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2. Reproduce

• Organisms reproduce like organisms.
• Life comes only from life. BIOGENESIS

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3. DNA Code of life

• Double helix composed of nucleotides
• Nucleotide sugar, phosphate group and base
• Structure - Deoxyribose sugars and phosphate
  groups
• 4 N bases make up rungs adenine, thymine,
  cytosine, and guanine
• A---T, C---G.carry information when read

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Structure of DNA nucleotides are repeating units
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4. Growth and Development

• Grow is to change in size.
• Develop is to change in shape and form.
• DNA directs patterns of growth and
  development.
• Hormones and Nutrition aid in changes and
  growth based on DNA direction.

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5. Obtain materials and use energy

• Producers (autotrophs) plants or any other
  organism that can make its own food sources.
• EX. Plants -- photosynthesis
• Consumers (heterotrophs) any organism that must
  consume another organism for food.
• EX. Herbivores, carnivores, omnivores

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6. Environmental Response

• Response a reaction to a stimulus
• Ex. Sit in the sun, sweat
• Eyes dilate in sunshine
• Plants lean toward sun (phototaxis)
• Sponges start/stop filter feeding based on
  water quality

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7. Maintain a stable internal environment

• Organisms are looking for HOMEOSTASIS
• -- process where organisms try to reach a
  steady-state or balance
• Keep in mind that living orgs NEVER reach a
  perfect balance

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8. Change over time -- evolution

• Evolve means to change over time
• EVOLUTION is the gradual accumulation of
  adaptations over time that help a group of
  organisms survive and be able to produce new
  offspring that would demonstrate the BEST
  combination of adaptations
• SURVIVAL OF THE FITTEST!!!

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Changes in beetle populations over time
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Evolutionary benefits can be due to better
camouflage