Environmental Biology (4)

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Environmental Biology (4)
2013-09-25 09:06:32

Chapter 4
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  1. Keystone Species
    Species that play roles affecting many other organisms in an ecosystem
  2. Why are sharks important?
    Because they remove injured or sick animals from ocean(ocean would be filled with dead and dying fish). We can learn why they almost never get cancer.
  3. What threats do sharks face?
    • Many Sharks are
    • caught for their valuable fins and then thrown back alive into the water (fins
    • removed). They vulnerable because they grow slowly, mature Late, and have only a
    • few offspring per generation.
  4. Name three reasons why insects are important to us?
    • -Many of the earth’s plants species depends on insects to pollinate
    • their flowers

    • -Insects that eat other insects such as Praying Mantis to help control
    • the populations of at least half the species of insects we call pests

    • -Some insects also play a key role in loosening and renewing the soil
    • that supports plant life on land
  5. Why are alligators so important?
    • -Because of its important ecological role in helping to maintain the sustainability of the
    • ecosystems in which it is found

    - Alligator eat large gar, a predatory fish, which helps maintain the population of game fish such as bass and bream that like to eat gar.

    -As alligators create gator hole and nesting mounds, they help to keep shore and open water areas free of invading vegetation
  6. The Theory of Evolution
    explains the idea that all species descended from earlier, ancestral species in other words, Life Comes From Life
  7. 3 reasons why the fossil record is uneven and incomplete.
    • -Some forms of life left no fossils
    • -Some fossils have decomposed.
    • -The fossils found so far represent probably only 1% of all species that have ever lived
  8. Describe how natural selection works.
    Is Genes mutate, Individuals are selected, and populations evolve such that they are better adapted to survive and reproduce under existing environmental conditions.
  9. What three conditions are necessary for evolution to occur by natural selection?
    • -Adaptive trait 
    • -Differential trait 
    • -Some traits favor individuals over others
  10. One common misconception about evolution is that humans descended from apes, what are two other common misconceptions
    • -Survival of the fittest means survival of the
    • strongest is another misconception; Fitness is a measure of reproductive success not strength 

    • -Another misconnection is organisms develop certain traits because they need them
    • (-Ex:giraffe ancestor had a gene for long necks that gave it an advantage over other members of its population in getting food, and that giraffe produced more offspring with long necks)
  11. What is the theory of plate tectonics?
    The continents are in constant motion and when they collide it makes a mountain
  12. Speciation? 2 Phases?
    Speciation is formation of two species from one species because of divergent natural selection in response to changes in environmental conditions

    • -Geographic Isolation
    • -Reproductive Isolation
  13. Background and Mass Extinction
    -Background extinction rate normal extinction of various species as a result of changes in local environmental conditions.

    -In Contrast, Mass Extinction is a significant rise in extinction rates above the background level
  14. How many mass extinctions have we had in the past?

    Are we currently in a mass extinction?
    -5 mass Extinctions

    -Yes because of human activities
  15. What occurs after a mass extinction and how long does it take to rebuild biological diversity?
    • -An increase in species diversity over several million years as new species have arisen to
    • occupy new habitants or to exploit newly available resources

    • -What occurs is the evolution of new species that can fill unoccupied ecological roles or newly
    • created ones
  16. What is the difference between an ecological niche and a habitat?
    • -Ecological Niche it is a species’ way of life in a community and includes everything that
    • affects its survival and reproduction, such how much water and sunlight it needs and etc.

    -Habitat is where specie lives while Niche is the pattern of living
  17. Generalist Species?  Give an example
    • Generalist Species have Broad Niches, which mean they can live in many different places,
    • eat variety of foods, and often tolerate a wide range of environmental conditions (ex; are flies, cockroaches’ mice rats’ raccoons and humans.)
  18. Specialist Species? Give an example
    • Narrow Niches they may be able to live in only one type of habitat, use just one or only few
    • types of food, or tolerate narrow range of climatic and other environmental conditions, (Ex; Shorebirds, Chinas Giant Panda)
  19. Cockroaches rule! What makes them so successful?
    They are Generalist, they can eat almost anything and live anywhere except in polar regions, some can go a month without food and can withstand a massive doses of radiation, can survive being frozen for 48 hours lastly they have a high reproductive rate
  20. Why should we care about the loss of global (or
    local) biodiversity?
    Because they play a major role in our ecosystems and can preform more than one task to the ecosystem
  21. Why are amphibians vanishing?
    • -Because of the rapid changes in the air and water over the past few
    • decades

    • -The eggs of frogs have no protective shell to block UV radiation or
    • pollution
  22. Why should we care about Amphibians Vanishing?
    • Because adult frog play an
    • important ecological role in our biological communities such as eat insects and
    • also we have been using them for medical treatment and they are sensitive to environment change are indicators of dramatic changed in our environment