Download Ch55Test - Milan Area Schools

Communities and Ecosystems: Chapter 55
Name:
Block:
Fill in the Blank
1. The total amount of ______________ assimilated by photosynthesis is called
gross primary production.
2. A ____________________ is defined as all organisms that get their energy from a
common source (e.g., all herbivores)
3. Detritivores reduce the remains of other organisms to mineral nutrients that can be
taken up by plants. An example of these are _________________.
4. The introduction of organisms where there were previously none due to a
disturbance is called ___________________.
5. Animals that eat primary producers are called ___________.
6. Organisms such as the beaver have a larger than expected impact on their
ecosystems. These are called __________________.
7. If decomposers where removed from an ecosystem all the minerals and energy
would _____________ in dead matter.
8. Only about ______________% of the energy present at one trophic level makes it
to the next trophic level.
9. A food web better explains what occurs in ecosystems because most organisms
______________ more than one other organism
10. ___________________ and __________________ drive the amount of primary
production found in an area.
Multiple Choice
11. Which of the following statements about food chains and energy flow through
ecosystems is false?
a. A single organism can feed at several trophic levels.
b. The lower the trophic level at which an organism feeds, the more energy is available.
c. Detritivores feed at all trophic levels except the producer level.
d. Food webs include two or more food chains.
e. All organisms that are not producers are consumers.
12. Assume that the energy transfer efficiency between trophic levels is 10 percent. How
much grain would be required to produce 70 kg of human biomass if the grain is eaten by
cows and the cows are eaten by humans?
a. 210 kg
b. 700 kg
c. 2,100 kg
d. 7,000 kg
e. 70,000 kg
13. If the removal of a species from a community has a greater effect on the structure and
functioning of the community than one would have predicted from the species’
abundance, then that species is most likely a(n)
a. keystone species.
b. carnivore.
c. herbivore.
d. early successional species.
e. mimic of another species.
14. The sea star Pisaster ochraceous is an abundant predator on the rocky intertidal
communities on the Pacific coast of North America. The sea star feeds preferentially on
the mussel Mytilus californianus. In the absence of the sea star, the mussel is a dominant
competitor. Predation by the sea star, however, creates bare areas. For this reason,
a. the number of species will be changed by the presence of the sea star, but the direction
of change cannot be predicted.
b. the variety of species will be unaffected by the presence or absence of the sea star.
c. the variety of species will be greater when the sea star is present than when it is absent.
d. the variety of species will be smaller when the sea star is present than when it is absent.
e. Mytilus will go extinct when the sea star is present.
15. Which of the following could not be used as an example of succession?
a. A landslide exposes bare rock. Eventually a forest is reestablished on the site.
b. An alien weed is introduced into the Hawaiian Islands. Eventually it displaces a native
plant, driving the native plant to extinction.
c. A freshly killed mouse decomposes.
d. A tree falls in the forest. Eventually a new tree replaces it.
16. The greatest amount of energy loss in ecosystems occurs through
a. photosynthesis.
b. respiration.
c. herbivory.
d. excretion.
e. digestion.
17. Photosynthetic plants are considered to be
a. heterotrophs.
b. consumers.
c. autotrophs.
d. detritivores.
e. predators.
18. Organisms that obtain their food from both primary consumers and another trophic
level are called
a. herbivores.
b. omnivores.
c. detritivores.
d. producers.
e. autotrophs.
19. All of the following are detritivores except
a. insects.
b. fungi.
c. wolves.
d. insects.
e. bacteria.
20. This type of energy drives almost all biological systems.
a.Solar
b.Chemical
c.Physical
d.Mechanical
e.Electrical