Chapter 12

Question 1

The process where one species gives rise to several others that exploit different features of the environment is known as

Answer 1

adaptive radiation

Question 2

As the population of a predator increases, the…

Answer 2

population of the prey species decreases

Question 3

When the trunk or limb of a tree provides the substrate on which an epiphytic orchid grows, the arrangement benefits the orchid (which gets nutrients from the air and moisture from aerial roots) while the tree is unaffected. This relationship is referred to as

Answer 3

Commensalism

Question 4

In most plant-pollinator interactions, plant species are pollinated by

Answer 4

multiple animal species and each animal species pollinates multiple plant species

Question 5

Adaptive radiation is often the result of

Answer 5

resource competition

Question 6

A remora feeds on the scraps that escape from a shark’s mouth while feeding. It has no clear positive or negative impact on the shark. This is an example of…

Answer 6

commensalism

Question 7

A food web is a better representation of a community than a food chain because most interactions among organisms…

Answer 7

are diffuse across a range of contexts

Question 8

An ecological niche is typically ___ dimension(s)

Answer 8

an unspecificed number of

Question 9

A realized niche can be larger than a fundamental niche….

Answer 9

when a commensal species expands another’s niche space

Question 10

As two competing species approach their respective carrying capacities, the growth rate of the other species…

Answer 10

slows down

Question 11

What are the 3 types of possible interactions?

Answer 11

Positive (+)
Detrimental (-)
Neutral (0)

Question 12

Define neutral interaction

Answer 12

Neither species affects the other (0 0)

Question 13

Define mutualism

Answer 13

Both species benefit from each other (+ +)

Question 14

Define commensalism

Answer 14

Benefit for one, other is unaffected (+ 0)

Question 15

Define amensalism

Answer 15

Detrimental to one, other is unaffected (- 0)

Question 16

Define predation

Answer 16

One species eats, other dies (+ -)

Question 17

Define parasitism

Answer 17

One species feeds on another, reducing the host fitness but not killing it (+ -)

Question 18

Define parasatoidism

Answer 18

One species uses another for reproduction, and its larvae feed on the host and eventually kill it (+ -)

Question 19

Define agent of mortality

Answer 19

Something that impacts a species deathrate. when a predator kills prey for an example

Question 20

As number of predators (Npredator) increases, what happens to prey population?

Answer 20

Number of prey captured and killed increases. Deathrate of prey increases (dprey).
Positive linear relationship.

Question 21

What is the equation for interspecific competition? (2 different species)

Answer 21

dN1 / dt = r1N1 (1-((N1+N2)/K1))

Question 22

What does the presense of a second species do to the carrying capacity of the 1st species?

Answer 22

If both species use same resources, they share the same carrying capacity. This leads to a reduction of the potential individuals of species 1.

Question 23

What is the equation using the competition coefficient alpha? What does alpha represent?

Answer 23

Alpha represents the impact of species 2 on species 1.
dN1 / dt = r1N1 (1-((N1+αN2)/K1))

Question 24

What is the equation using the competition coefficient beta? What does beta represent?

Answer 24

Beta represents the impact of species 1 on species 2.
dN2 / dt = r2N2 (1-((N2+βN1)/K2))

Question 25

Define coevolution

Answer 25

Process in which 2 species undergo reciprocal evolutionary change through natural selection.

Question 26

What are the 2 main reasons for coevolution?

Answer 26

• Counter-adaptive changes attempting to thwart other species
• Reinforce the effect of adaptive change in mutually beneficial interactions

Question 27

What can coevolution lead to?

Answer 27

Divergence of phenotypes due to a desire of wanting to reduce competition. Can also lead to mimicry between species.

Question 28

Define ecological niche

Answer 28

Species is the range of physical and chemical conditions under which a species is able to survive and reproduce

Question 29

Define competitive exclusion principle

Answer 29

2 species can’t coexist if they occupy exactly the same niche.

Question 30

Define multidimensional hypervolume

Answer 30

Each dimension is a variable that relates to a specific resource. There are n# of dimensions that an organism lives in.

Question 31

Define fundamental niche

Answer 31

Environmental conditions in which a species can survive and reproduce

Question 32

Define realized niche

Answer 32

Portion of the fundamental niche that a species actually uses as a result of interactions with other species