Identify the choice that best completes the statement or answers the question

2 Which of the following relationships exists between the frog and the mayfly?

3 Which output from a bear can be used by salmonberry plants in a forest habitat?

4 Adding habitat is a solution to the problem of decreased butterfly populations in prairie ecosystems. What could be an unintended consequence of adding habitat for butterflies?

5 Muskrats are omnivores that live in burrows on the pond banks. Which of the following would most likely lead to an increase in the size of the muskrat population over time?

6 Which of the following organisms is correctly matched to its role in the pond ecosystem?

7 A correlation exists between the number of cases of moose brainworm disease and the density of the deer population.

Which of the following statements gives the best explanation for this relationship?

A	High deer population density causes individual deer to reproduce more.
B	High deer population density speeds up the life cycle of the roundworm.
C	High deer population density attracts more moose to an area where they will become infected.
D	High deer population density results in more larvae-infected waste for snails to encounter in an area.

8 Which of the following lemurs would be classified as a secondary consumer?

9 The moose belongs to which trophic level in an ecosystem?

10 Some species of penguins, such as chinstrap penguins, depend on open water for their survival. Other species of penguins, such as Adélie penguins, depend on ice. Over the last 20 years, the population size of chinstrap penguins has increased, and the population size of Adélie penguins has decreased. Which of the following most likely caused these changes in population size?

11 A simple food web is shown below.

Which of the following is most likely to lead to the greatest decrease in the deer mouse population?

12 A company that produces pesticides conducts an experiment to test the effectiveness of their newest product. The scientist involved in the development of the pesticide is the one who will interpret the results. Why is this a problem?

13 Geothermal energy can be converted from hot water or steam from deep within Earth’s surface and transformed into electricity. One disadvantage of geothermal energy is that

14 One kind of bacteria lives, secretes enzymes into, and consumes dead organic matter in areas without oxygen. These bacteria can be classified as

15 Which organism in the aquatic food web below gets energy directly from the Sun?

16 If a single plant species is removed from a food web, then most likely —

17 Which order of diagrams would show primary succession in an area that had never before been occupied by living organisms?

A	C, A, B, D	C	D, B, C, A
B	B, A, C, D	D	A, C, B, D

18 How would the development of hybrid cars minimize the effects of human population growth on the environment?

F	by increasing noise pollution
G	by increasing smog production
H	by decreasing dependence on fossil fuels
J	by decreasing the number of people traveling on highways

19 A horse eats an apple from a tree. Which statement best explains this relationship?

A	Both the horse and the tree are heterotrophs.
B	The horse, a heterotroph, is consuming food from an autotroph.
C	Both the horse and the tree are neither autotrophs nor heterotrophs.
D	The horse, an autotroph, is consuming food from another autotroph.

20 Which best describes the interaction between autotrophs and heterotrophs?

F	One competes with the other for access to sunlight and soil.
G	One decomposes the other to release nutrients back into the soil.
H	One helps produce the other in a mutually beneficial relationship.
J	One consumes the other to use energy that originally came from the Sun.

21 One problem with imposing heavy fines on businesses that do not meet legal or environmental standards with their waste emissions, is that such actions may result in

A	political opposition from the business’ supporters.
B	the businesses increasing their need for fossil fuels.
C	the businesses increasing their number of employees.
D	prices of the services offered by the businesses going down.

22 What is a main difference between primary succession and secondary succession?

F	Primary succession happens slowly, and secondary succession happens rapidly.
G	Small plants grow first during primary succession, while large trees grow first during secondary succession.
H	Primary succession occurs after a natural disaster, and secondary succession occurs before a natural disaster.
J	Primary succession is the colonization of new sites, and secondary succession is colonization of previously inhabited sites.

23 A certain light-producing microbe finds shelter and food in the skin of a fish. This relationship would be considered mutualism if the light from the microbe

A	helps the fish find suitable mates.
B	causes harmful mutations in the fish.
C	makes the fish more easily preyed upon.
D	makes no difference in the life of the fish.

24 A land developer wants to control a population of hawks. He decides to solve the problem by clearing out the land’s fields. How will this action most likely control the population?

F	The population of hawks will increase due to decreased competition.
G	The hawks will experience more crowding and the population will decline.
H	There will be fewer predators of the hawks, so their population will increase.
J	The food supply of the hawks will decrease, causing the population of hawks to decrease.

25 A plan to convert and burn unsold food as biological fuel can be environmentally beneficial because it

A	restores wetlands.	C	reduces air pollution.
B	limits landfill use.	D	decreases biodiversity.

26 In Calhoun County, Arkansas, a local timber company is now required to grow pine trees for 45 years before harvesting instead of the normal 20 years. This would increase biodiversity in Calhoun County through the

F	reduction of pollution.	H	elimination of extinction.
G	preservation of habitats.	J	simplification of food webs.

27 Which best describes the interaction between autotrophs and heterotrophs?

A	One competes with the other for access to sunlight and soil.
B	One decomposes the other to release nutrients back into the soil.
C	One helps produce the other in a mutually beneficial relationship.
D	One consumes the other to use energy that originally came from the Sun.

28 Which presents the correct order of biomes from least biodiversity to most biodiversity?

F	tundra, taiga, temperate grassland, rainforest
G	taiga, tundra, temperate grassland, rainforest
H	tundra, taiga, rainforest, temperate grassland
J	taiga, tundra, rainforest, temperate grassland

29 The figure below shows the number of plants and animals necessary to support the life of one high-level consumer in a temperate grassland biome.

The figure represents the flow of energy through

A	different trophic levels in most ecosystems
B	soil, plants, and animals during the nitrogen cycle
C	different organisms within a single level of most food webs
D	the atmosphere, land, and bodies of water during the water cycle