Bio 9 Chapter 4.txt

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Bio 9 Chapter 4.txt
2011-09-16 01:10:33

Biodiversity and Evolution
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    • author "me"
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    • description "Biodiversity and Evolution"
    • fileName "Bio 9 Chapter 4"
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    • Define species.
    • A set of individuals that can mate and produce fertile offspring.
  1. True/False: The number of identifed species is 3 million.
    False. It is 2 million.
  2. How many species are there likely to be?
    10-14 million.
  3. What is the bottleneck effect?
    Due to the large number of a species that has died, there is less variablity in the genes.
  4. What are biomes?
    The terrestrial portion of the biosphere.
  5. How do insects help the environment?
    They help with pollination, pest control, and soil renewal.
  6. What is the theory of evolution?
    That all species descnded from earlier, ancestral species.
  7. Explain natural selection.
    Genes of some individuals give rise to traits that enhance survivability and reproduction - passing on these traits.
  8. How does a population change over time?
    It becomes genetically different.
  9. How does genetic variability occur?
    Through random, sometimes spontaneous, changes in DNA molecules, and external agents (such as radiation). This can create an inheritable trait.
  10. True/False: Inherited traits are advantageous, neutral, or deletrious.
  11. True/False: You have a higher chance of inheriting a deletrious trait.
    False. The less beneficial a trait is, the lesser the chance that you'll get it.
  12. Define adaptive traits.
    Genetically favorable traits that increase survivorship and reproduction.
  13. What are the three outcomes for a species faced with environmental change?
    The species can either adapt through evolution, migrate, or become extinct.
  14. How does evolution occur by natural selection.
    Genes mutate, individuals and traits are selected, and populations evolve, leaving them better suited to survive current environmental conditions.