Honors Biology
Unit: Ecology
Chapters 2,3,4
Test-Ecology
Name ______________________________________
Date ____________________________ Per _______
Directions: Pick the one best answer for each multiple choice question. Write complete and legible
answers for each short answer question.
1. ______An abiotic factor affecting the behavior and survival of organisms, such as birds and insects, in a community is
the
A. number of secondary consumers.
B. number of daylight hours.
C. number of herbivores.
D. appearance of harmful bacteria.
2. ______A new species of mouse is introduced to an environment. As the mice reproduce
and the population grows, food resources decrease and predation by hawks
increases. Eventually, the number of mice levels off so that the rate of birth
equals the rate of death. This nearly constant number of organisms,
represented by the dotted line in the diagram, is called
A. carrying capacity.
B. exponential growth.
C. linear growth.
D. competition.
3. ______A student is building a terrestrial biome model that represents the greatest biodiversity on Earth. The model will
be of a
A. taiga.
B. temperate forest.
C. tropical rain forest.
D. tundra.
4. ______Some plants and animals have adaptations that enable them to survive in a desert ecosystem. Most of these
adaptations are a response to which abiotic factor?
A. number of consumers
B. number of producers
C. amount of rainfall
D. cloud coverage
5. ______Some organizations are buying up sections of forest land. Once purchased, forests within the sections will never
be cut down. The most obvious goal of protecting these sections of forest is to
A. cause extinction.
B. prevent overpopulation of trees.
C. maintain diversity of the environment.
D. farm.
6. ______One biotic factor that limits the carrying capacity of any habitat is the
A. availability of water.
B. level of atmospheric oxygen.
C. activity of decomposers.
D. amount of soil erosion.
7. ______The importation of organisms such as the Japanese beetle to areas where they have no natural enemies best
illustrates
A. the use of abiotic factors to reduce pests.
B. the selection of species to mate with each other to produce a new variety.
C. human attempts to protect extinct species.
D. a human activity that disrupts existing ecosystems.
8. ______ A greater stability of the biosphere would most likely result from
A. decreased finite resources.
B. increased consumer population.
C. increased biodiversity.
D. increased deforestation.
9. ______ Which factor is primarily responsible for the destruction of the greatest number of habitats?
A. human population growth
B. decreased use of renewable resources
C. spread of predatory insects
D. epidemic diseases
10. ______ The graph below shows changes in population numbers over time. What is the best way to describe the
relationship between these two populations?
A. symbiotic
B. predator-prey
C. invasive
D. endangered
11. ______ Water from nearby rivers or lakes is used to cool down
the reactors in nuclear power plants. The release of
this heated water back into the river or lake would
most likely result in a(n)
A. increase in sewage content.
B. change in the number of mutations in plants in the water.
C. change in the biodiversity of the habitat.
D. decrease in the amount of sunlight necessary for photosynthesis in the water.
12. ______ An energy pyramid may show
A. the flow of energy in an ecosystem.
B. the rate of natural selection.
C. a food chain.
D. predators v. prey.
13. ______ Which organism would be at the base of an energy pyramid?
A. autotroph
B. carnivore
C. omnivore
D. heterotroph
14. ______ An energy pyramid represents the following organisms: grass, bird, grasshopper, and fox. Energy from which
organism is consumed by all the others?
A. grass
B. bird
C. grasshopper
D. fox
15. ______ The total weight of living matter at each trophic level of an energy pyramid is called
A. kilojoules of energy.
B. bioweight.
C. biomass.
D. food mass.
16. ______ The ecological niches of three bird species are shown below. What is the advantage of each bird species having
a different niche?
A. More energy is available the higher a bird feeds.
B. More abiotic resources are available for each bird.
C. Fewer predators are present.
D. There is less competition for food.
17. ______ Changes in an ecosystem result from all of the following
except
A. climate.
B. human activity.
C. introduction of nonnative species.
D. stability in population size.
18. ______ Fluctuations in population size in an ecosystem are
determined by the relative rates of all of the following
except
A. birth.
B. immigration and emigration.
C. death.
D. overfeeding.
19. ______ Rabbits introduced into Australia over 100 years ago have become a serious pest to farmers. Rabbit
populations increased so much that they displaced many native species of plant eaters. What is the most
logical explanation for their increased numbers?
A. Rabbits have a high death rate.
B. There are few effective predators.
C. Additional rabbit species have been introduced.
D. There is an increase in rabbit competitors.
20. ______ Based on the food pyramid below, which organism has the least amount of energy available to it?
A. grass
B. grasshopper
C. starling
D. owl
21. ______ In a pond, the primary producer is a green alga, Spirogyra; the primary consumer is the crustacean, Daphnia;
the secondary consumer is a small fish, the bluegill; and the tertiary consumer is a larger fish, the smallmouth
bass. What changes can be expected in the pond if the Daphnia are killed with pesticides?
A. The Spirogyra population will probably die.
B. The bluegill population will probably increase.
C. The Daphnia population will eat something else.
D. The smallmouth bass population will die.
22. ______ For the food chain shown, which of the following changes would have the most severe consequences?
A. a drastic decrease in rainfall, causing drought
B. the poaching of predatory hawks by game hunters
C. the introduction of a second predator that eats field
mice
D. a parasitic infestation that reduces the cricket population
The graph below shows the birth rate and death rate for a population during the 1900s.
23. _____ From 1900 to 2000, the population has
A. increased.
B. decreased.
C. stayed the same.
D. increased until 1930, and then decreased.
The diagram represents a Coastal Food Web.
24. ______ Global warming causes an increase in coastal water temperatures. Increased coastal water temperature causes
a decrease in reproduction of krill. Which of these would most likely experience an increase in population?
A. gull
B. herring
C. anchovy
D. phytoplankton
Use the information and the drawing below to answer questions 25-27.
The desert climate is caused by geographic conditions such as location, high atmospheric
pressure, and proximity of mountain ranges. Average desert rainfall amounts are usually
less than 50 cm per year. Soil in deserts is coarse, sandy, and rocky. Desert plants and
animals have specialized characteristics that help them survive in the harsh environment.
An example is the Saguaro cactus. The Saguaro has a shallow root system with a main
taproot and other roots that radiate out and collect surface water. The trunk of the
Saguaro has the ability to expand while storing water. The sweet-nectar flowers of the
Saguaro attract white-winged doves, bats, and other animals. These animals feed on the
nectar. They are necessary for cross-pollination. Cross-pollination occurs when the pollen
of a flower is carried to a flower on another plant. The illustration below shows the
Saguaro cactus.
25. ______ Which advantage is the most likely result of cross-pollination to Saguaro cacti?
A. disease resistance
B. variation within the species
C. larger cacti offspring in each generation
D. increased number of animals that drink nectar
26. ______ Which of these adaptations is most important for the Saguaro to survive long periods of drought?
A. deep roots
B. sweet nectar
C. large flowers
D. expanding trunk
27. ______ Which of these best describes the ecological relationship between white-winged doves and the Saguaro
cactus?
A. mutualism
B. competition
C. parasite-host
D. predator-prey
Methyl mercury is a toxic substance that can harm the nervous system. Some fish are contaminated with high levels of
methyl mercury. In many places, these fish are an important food source. Experiments are being conducted to determine
how many meals of contaminated fish can be safely consumed. The table below shows the concentration of methyl
mercury in the fish and the number of meals that can be safely consumed per month.
28. ______ According to this table, which fish would be safest to eat?
A. common carp
B. channel catfish
C. largemouth bass
D. yellow perch
The data collected during this experiment are summarized in the graph below.
29. ______ The graph has been constructed incorrectly. Which of these needs to be corrected in order to improve the
graph?
A. The axes are labeled with inappropriate intervals.
B. The dependent and independent variables are on wrong axes.
C. The title is inconsistent with the investigation.
D. One or both axes are missing units.
30. ______ A new species is introduced into an area. This can have harmful effects on species already inhabiting the area.
The harmful effects are most likely a result of
A. succession
B. mutualism
C. competition
D. commensalism
Use the following information to answer questions 31-32.
Scientists have observed that when a largemouth bass tries to eat a whirligig beetle, the fish is likely to get more than just
a meal. Once inside the mouth of a bass, the beetle releases a foul-tasting substance into the fish’s mouth. The fish
responds to this by swishing the beetle around in its mouth, spitting the beetle out into the water, and scooping the beetle
back into its mouth. The bass is exhibiting a “flushing” behavior. Unlike other insects, whirligig beetles do not release all of
their foul-tasting substance the first time they are pulled into a predator’s mouth. Each time the bass scoops the beetle
back into its mouth, more of the substance is released. The bass must exhibit “flushing” again and again. If the bass tires of
“flushing” before the beetle runs out of its foul-tasting substance, the beetle can avoid becoming the bass’s next meal.
31. ______ The ecological relationship between largemouth bass and whirligig beetles is best described as
A. predator-prey
B. parasite-host
C. mutualism
D. commensalism
32. ______ Which research question about the largemouth bass and whirligig beetle would best match the scientists’
observations?
A. How long do beetles spend rinsing their food?
B. What is the favorite food of a largemouth bass?
C. Which insects produce the most foul-tasting substances?
D. Does the slow release of a foul-tasting substance increase survival?
A partial food web is shown below.
33. ______ Which of the following changes is most likely to occur if the sparrow
population decreases?
A. The fox population decreases.
B. The hawk population increases.
C. The grasshopper population competes less with the praying
mantis population.
D. The hawk population and the fox population prey more heavily
on grasshoppers.
34. ______ A disease resulting in the deaths of one third of a dense population
of bats in a cave would be a
A. density-dependent limiting factor
B. result of exponential growth
C. density-independent limiting factor
D. nutrient-limiting factor
35. ______ As DDT moves up the trophic levels in food chains, or food webs, its concentration
A. stays the same.
B. increases.
C. decreases.
D. is eliminated.
PART B: Short Answer
1. Cattle-like animals called wildebeests live in Africa. The wildebeest population decreased for many years
because of a fatal virus. The virus was eliminated in the 1960s by vaccinating the wildebeests against the
virus. The graph below shows changes in the size of the wildebeest population from 1961 to 1983.
a. Describe the effect of the vaccinations on the death rate in the wildebeest population.
b. Explain the change in the size of the population from 1961 to 1977 in terms of birth rate and
death rate. Assume immigration and emigration rates were equal during this time.
c. Based on the graph, describe what happened to the wildebeest population size from 1977 to
1983 and explain why this pattern most likely occurred.
2. What are invasive species? How are they a threat to biodiversity?
3. Human impact is the biggest influence on environmental change. Give three specific examples of
human impact and the influence it has had on our biosphere.