1. An example of a biotic factor is

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• 1. An example of a biotic factor is
• The number of worms in the soil
• The amount of leaf liter (dead leaves) in the
  soil
• The pH of the soil
• Both A and B

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• The interaction between the different species
  in an area and their physical surroundings is
  called
• a community
• a population
• an ecosystem
• a biosphere

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• 3. A forest has 9,000 trees in an area of 10
  square miles. What is the population density
  for the trees in this forest?
• 90 trees-mi2
• 90 trees/mi2
• 900 trees-mi2
• 900 trees/mi2
• 90,000 trees-mi2
• 90,000 trees/mi2

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• To calculate population density divide the
  population size by the area.
• Population Density Population size / Area
• A population of 9,000 trees in an area of 10 mi2
  has a density of 900 trees/ mi2.
• The unit for the population of trees in this
  forest is trees / mi2 pronounced trees per square
  mile because the formula involved dividing the
  trees by the area.

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• A full description of an organisms role in an
  ecosystem, that includes its position in the
  food web and how it interacts with other species
  is its
• habitat
• niche
• biotic capacity
• abiotic capacity

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• Organisms that can produce their own food,
  using sunlight or in a few cases certain chemical
  compounds, are called
• producers
• autotrophs
• heterotrophs
• A and B
• A and C

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• 6. An example of a chemosynthetic organism is
• a yeast cell that is able to ferment grapes to
  produce alcohol
• a bacteria found in hydrothermal vents that is
  able to produce organic food molecules using the
  energy found in certain volcanic compounds
• both A and B
• neither A nor B

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• Which of the following words in synonymous
  with the word consumer?
• Autotroph
• Herbivore
• Scavenger
• Heterotroph

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• The diet of a bear includes both meat and
  vegetation such as berries and bulbs. With this
  type of diet, bears are classified as
• Carnivores
• Scavengers
• Omnivores
• Herbivores
• Detritivores

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• A trophic level is
• a step in a food chain.
• the amount of sunlight present in an ecosystem
• the average temperature in an ecosystem
• the average amount of precipitation in an
  ecosystem

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• A food chain (or web) forms an energy pyramid,
  in which the widest part of the pyramid with the
  greatest amount of stored energy and biomass is
• a top consumer
• an autotroph
• an herbivore
• a decomposer

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• 11. A food chain in a pond begins with algae that
  are eaten by mayfly nymphs which serve as food
  for sunfish which are then consumed by great blue
  heron.
• (algae ? mayfly nymph ? sunfish ? great
  blue heron )
• If this pond becomes contaminated with
• mercury, which organism would likely become most
  contaminated with this toxin?
• The algae
• The mayfly nymph
• The sunfish
• The great blue heron

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• 12. If you compared the amount of mercury in a
  tuna (a larger fish that is higher on the food
  chain) to that in a herring (a smaller
  plankton-eating fish) it would likely have
• A. A greater total amount of mercury
• B. A higher concentration (grams of mercury per
  pound of body mass)
• C. Both A and B
• D. Neither A nor B

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Review Remember that food chains form energy
pyramids with less biomass for each level you
move up the food chain. (More algae is needed to
feed the mayfly nymphs etc.) This pattern is
due to the 2nd Law of Thermodynamics that states
that in any energy conversion, some energy will
be degraded into less useful heat energy.
Therefore, the top consumer generally has the
greatest concentration of toxins, since the same
amount of toxin is present in a smaller quantity
of biomass. The top consumer has had to consume a
greater amount of food from the lower levels.
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• 13. The carrying capacity for the rabbit
  population is
• 3
• 4
• 30
• 60
• 65

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• 14. Which of the following could cause an
  increase in the carrying capacity of the rabbit
  population?
• An increase in the supply of food
• An increase in the birth rate
• Both A and B
• Neither A nor B

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• 15. The initial phase of a logistic growth graph
  shows
• an exponential increase in the population
• a steep linear increase
• a decline in population
• a gradual linear increase

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Organisms generally reproduce at a rate that
would allow for exponential growth. The carrying
capacity of a population is caused by the factors
that limit its growth (food supply, predators
etc.) The carrying capacity is not a fixed
quantity. If the limiting factors change than
the carrying capacity will also change.
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• 16. Which type of species would have an
  advantage if there is an unstable environment?
• Generalist
• Specialist

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• D
• C
• D
• B
• D
• B
• D
• C
• A
• B
• D
• C
• D
• A
• A
• A