Chapter 5 How Ecosystems Work

Question 1

an atmospheric gas that increases when fossil fuels are burned

Answer 1

carbon dioxide

Question 2

evidence of excessive fertilizer use

Answer 2

algal bloom

Question 3

a final and stable community

Answer 3

climax community

Question 4

a type of succession that occurs on abandoned farmland

Answer 4

old-field succession

Question 5

a gradual process of change and replacement of the types of species in a community

Answer 5

ecological succession

Question 6

a common type of succession that occurs on a surface where an ecosystem has previously existed

Answer 6

secondary succession

Question 7

What is the ultimate source of energy for almost all organisms?
a. producers
b. consumers
c. the sun
d. bacteria

Answer 7

c. the sun

Question 8

Which of these consumers might depend on a rabbit for its energy?
a. grasshopper
b. coyote
c. cow
d. horse

Answer 8

b. coyote

Question 9

What term is used to describe a linear sequence in which energy is transmitted from one organism to the next as each organism eats another organism?
a. food web
b. food chain
c. trophic level
d. energy pyramid

Answer 9

b. food chain

Question 10

What term is used to refer to the many feeding relationships that are possible in an ecosystem?
a. food web
b. food chain
c. energy pyramid
d. energy transfer

Answer 10

a. food web

Question 11

Which organism would occupy the level on an energy pyramid with the most energy?
a. bobcat
b. bird
c. grasshopper
d. carrot

Answer 11

d. carrot

Question 12

In the carbon cycle, where do the producers get their carbon?
a. the atmosphere
b. carbohydrates in plants
c. fossil fuels
d. animal remains

Answer 12

a. the atmosphere

Question 13

Where are fossil fuels located?
a. on the surface of Earth
b. deep within Earth
c. beneath the ocean floor
d. all of the above

Answer 13

d. all of the above

Question 14

How do lichens contribute to primary succession?
a. Lichens begin to break down rock to form soil.
b. Lichens decompose organic matter from animals and plants.
c. Lichens are nitrogen-fixing bacteria.
d. Lichens convert carbohydrates into fossil fuels.

Answer 14

a. Lichens begin to break down rock to form soil.

Question 15

Where would you most likely find nitrogen-fixing bacteria?
a. in leaves of trees
b. on the roots of legumes
c. on dust particles in the atmosphere
d. in blue-green algae

Answer 15

b. on the roots of legumes

Question 16

What type of vegetation would you expect to find on an abandoned farm that has been undisturbed by humans for 150 years?
a. short grasses
b. shrubs
c. young pine trees
d. tall, mature oak trees

Answer 16

d. tall, mature oak trees

Question 17

Consumers are organisms that
a. eat only other animal species.
b. get their energy by eating other organisms.
c. are also known as self-feeders.
d. occupy an ecosystem’s lowest energy level.

Answer 17

b. get their energy by eating other organisms.

Question 18

The energy consumed by organisms
a. can be stored in fat and sugar molecules.
b. remains constant at all trophic levels.
c. undergoes magnification in food chains.
d. is not partially lost during digestion.

Answer 18

a. can be stored in fat and sugar molecules.

Question 19

Which of these is a large reservoir of nitrogen that is unusable by most organisms?
a. soil
b. atmosphere
c. ocean
d. space

Answer 19

b. atmosphere