lesson 21

Question 1

What does community ecology study?

Answer 1

How different species interact with one another in a shared area.

Question 2

What is a biological community?

Answer 2

All organisms living in one place.

Question 3

How can communities be described?

Answer 3

By species richness, species diversity, and primary productivity.

Question 4

Do communities stay the same over time?

Answer 4

No, they change over space and time

Question 5

What is an ecological niche?

Answer 5

All the ways an organism uses the resources of its environment.

Question 6

What is a fundamental niche?

Answer 6

The full range a species could use without competition.

Question 7

What is a realized niche?

Answer 7

The range a species actually uses due to competition and interactions.

Question 8

What is interspecific competition?

Answer 8

Competition between different species.

Question 9

What are two types of interspecific competition

Answer 9

Interference competition (direct fighting)
exploitative competition (resource use).

Question 10

What did Connell’s barnacle study show?

Answer 10

Competition can restrict a species’ realized niche.

Question 11

What is the competitive exclusion principle?

Answer 11

No two species can occupy identical niches forever when resources are limiting.

Question 12

What is resource partitioning?

Answer 12

Species dividing resources to reduce competition.

Question 13

What is character displacement?

Answer 13

Evolution causing species traits to diverge, reducing competition.

Question 14

What is predation

Answer 14

Consuming one organism by another (includes herbivory)

Question 15

What are some plant defenses against herbivores?

Answer 15

Thorns, toxins (secondary metabolites), silica deposits.

Question 16

What are animal defenses against predators?

Answer 16

Chemical defenses, warning coloration, cryptic coloration.

Question 17

What is Batesian mimicry?

Answer 17

A harmless species mimics a harmful one.

Question 18

What is Müllerian mimicry?

Answer 18

Two harmful species mimic each other.

Question 19

mutualism

Answer 19

A symbiosis where both species benefit.

Question 20

parasitism

Answer 20

A symbiosis where one species benefits and the other is harmed.

Question 21

parasitoids

Answer 21

Insects that lay eggs on or in hosts, eventually killing them.

Question 22

How can parasites manipulate host behavior?

Answer 22

They alter brain function to increase transmission (e.g., Toxoplasmosis).

Question 23

commensalism

Answer 23

A relationship where one species benefits and the other is unaffected.

Question 24

How can predators reduce competition among prey

Answer 24

By lowering prey population sizes and controlling dominant species.

Question 25

What are indirect effects in ecology?

Answer 25

When two species affect each other through a third species.

Question 26

What is a keystone species?

Answer 26

A species whose impact on the community is greater than expected based on its abundance

Question 27

ecological succession

Answer 27

A gradual change in community species composition over time

Question 28

What is primary succession?

Answer 28

Succession that starts on bare rock or land with no soil.

Question 29

What is secondary succession?

Answer 29

Succession that occurs after a disturbance, where soil and some organisms remain.

Question 30

What are the three processes in succession?

Answer 30

Establishment (r-selected species) facilitation (helping other species) inhibition (k-selected species dominate).

Question 31

How does species richness typically change during succession?

Answer 31

It usually grows, then may level off or decline.

Question 32

How do disturbances affect communities?

Answer 32

they structure the community by influencing species richness and succession.