Ecology Core Review Test
A freshwater lake has a muddy bottom, which is
home to different types of photosynthetic algae and
other organisms. Many species of fish feed on the
algae, and the fish are food for birds, fox, and bears.
5. Which of the following organisms typically fill the role
of decomposers in an ecosystem?
a. grasses and ferns
b. mushrooms and bacteria
c. mice and flies
d. snakes and birds
1. Make an inference about what would happen to the
algae population if the amount of sunlight is increased.
a. The algae population will increase due to
photosynthesis
b. The algae population will increase due to
predation
c. The algae population will decrease due to
predation
d. The algae population will remain constant
2. What type of relationship exists between the fish and
the birds?
a. host – parasite
b. producer – consumer
c. predator - prey
d. producer – predator
3. Algae experience extreme growth in the presence of
phosphorus. Predict what might happen to the lake if
inconsiderate hikers washed their laundry in the lake
and used high-phosphorus content detergent.
a. The algae would be killed, and the fish population
would decrease.
b. The algae would grow faster, and other lake
organisms would suffer.
c. The algae would be killed, and the fish population
would increase.
d. The algae would be unchanged, so the lake will be
unharmed.
4. Although three different bird species all live in the
same trees in an area, competition between the birds
rarely occurs. The most likely explanation for this lack
of competition is that these birds
a. occupy different niches
b. eat the same food
c. have a limited supply of food
d. live in the same part of the tree
This energy pyramid represents how biological energy
flows through an ecosystem: from algae to zooplankton
to krill to fish to osprey.
6. How does the energy arrive to the algae level?
a. from the water
b. from the vitamins and minerals in the water
c. from the zooplankton
d. from sunlight
7. How might the krill be classified in this ecosystem?
a. as first level consumers
b. as second level consumers
c. as producers
d. as decomposers
8. If 10,000 Kcalories of energy is produced by the algae
through photosynthesis, how much energy is available
for the zooplankton to use?
a. 10,000 Kcalories
b. 5,000 Kcalories
c. 1,000 Kcalories
d. 100 Kcalories
9. The fish will convert the energy supplied by the krill
into what form of energy to be used by their cells?
a. mechanical energy
b. chemical energy
c. heat energy
d. light energy