Free Practice Quiz Question List

11. Populations, Communities, and Ecosystems Online Quiz Questions

Use this free practice quiz with 20 questions to review 11. Populations, Communities, and Ecosystems, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

Energy flows through ecosystems, whereas matter cycles through organisms and the physical environment.

A
True
B
False

Choose one

1 point

Why are ecological pyramids of energy always upright?

A
Because producers always have the smallest biomass
B
Because energy is lost during each transfer between trophic levels
C
Because consumers cannot occupy more than one trophic level
D
Because decomposers prevent energy from entering food webs

Written response

1 point

What ecological term means the number of different species present in a community?

Fill in the blank

1 point

An ecosystem consists of a community plus its .

Choose one

1 point

A population grows rapidly at first, then slows as food and nesting space become limited. Which model and curve best describe this pattern?

A
A J-shaped curve that accelerates without slowing
B
An irregular line caused only by random sampling error
C
An S-shaped curve that levels off near carrying capacity
D
A straight line showing a constant increase per generation

Choose all

1 point

Which factors are generally density-dependent regulators of population size? Select all correct choices.

A
Competition for food or space
B
A hurricane affecting a coastal population
C
Predation
D
Infectious disease spreading among crowded individuals

True or false

1 point

Secondary succession is generally faster than primary succession because it begins with soil or other biological remnants already present.

A
True
B
False

Written response

1 point

In a mark–recapture study, 40 individuals are marked initially, 50 are captured later, and 10 of those later captures are marked. What population size is estimated? Enter the number of individuals.

Fill in the blank

1 point

An interaction in which one species benefits and the other is not significantly affected is . An interaction in which both species benefit is .

Choose one

1 point

Community A contains 25 individuals of each of four species. Community B contains 97 individuals of one species and 1 individual of each of three other species. Which comparison is correct?

A
Community B has greater richness and greater evenness
B
Both communities have the same richness, but Community A has greater evenness
C
Both communities have the same richness, but Community B has greater evenness
D
Community A has greater richness, but both have the same evenness

Choose all

1 point

Which statements correctly describe energy flow and feeding relationships in ecosystems? Select all correct choices.

A
Primary producers capture energy and convert it to chemical energy
B
Only a fraction of energy becomes biomass available to the next trophic level
C
Energy is recycled through ecosystems in the same way as matter
D
A food web represents multiple interconnected feeding relationships

Open ended

1 point

Design an investigation to test whether plant density affects individual plant growth. Describe the treatments, key controls, replication, measurements, and the ecological prediction you would make.

Choose one

1 point

A newly cooled lava flow exposes bare rock with no soil. Which type of succession is expected, and why?

A
Secondary succession, because lava always contains mature soil
B
Secondary succession, because disturbance automatically leaves seeds
C
Primary succession, because the exposed surface lacks soil and a previous community
D
Primary succession, because all succession begins with annual plants

Written response

1 point

An ecosystem has a gross primary productivity of 120 energy units per square metre per year, and producers use 70 energy units per square metre per year for respiration. What is the net primary productivity? Enter the number in energy units per square metre per year.

Choose one

1 point

Researchers count 240 meadow plants in a quadrat survey covering 12 square metres. What is the estimated population density?

A
2 individuals per square metre
B
20 individuals per square metre
C
200 individuals per square metre
D
2,880 individuals per square metre

True or false

1 point

True or false: In an ecosystem, energy generally flows through the system while chemical matter is continually recycled.

A
True
B
False

Choose one

1 point

Two plant species require exactly the same limited nutrients, light conditions, and growing space in a stable habitat. According to the competitive exclusion principle, what is the most likely long-term outcome?

A
They will always form a mutualism.
B
They will coexist indefinitely because competition increases diversity.
C
One species will tend to outcompete the other unless resource use differs.
D
Both species will immediately become foundation species.

Written response

1 point

An ecosystem is heavily disturbed by a fire but returns to a community resembling its former state within several years. What ecological property does this recovery demonstrate?

Choose one

1 point

Community A contains 25 individuals of each of four species. Community B contains 97 individuals of one species and 1 individual of each of three other species. Which community has greater species evenness?

A
Community B, because one species is dominant
B
Community A, because its species have more similar abundances
C
Both communities equally, because richness and evenness always have the same value
D
Neither community, because evenness applies only to genetic diversity

Choose one

1 point

In the food chain grass → grasshopper → frog → snake, which arrow correctly represents the transfer of energy when a frog eats a grasshopper?

A
grasshopper → frog
B
frog → grasshopper
C
grass → grasshopper
D
frog → snake