13 - Species Interactions, Population Dynamics, and Natural Selection

Question 1

1) In most flowering plants, successful reproduction requires that ________ (male gametes) from
one individual be transported to the female organ (stigma) of another flowering individual.

Answer 1

pollen

Question 2

2) When each of two species benefits from their interaction, the relationship is referred to as
________.

Answer 2

mutualism

Question 3

3) When one species reduces or adversely affects the population of another, but the affected
species has no influence in return, the relationship is referred to as ________.

Answer 3

amensalism

Question 4

3) When one species reduces or adversely affects the population of another, but the affected
species has no influence in return, the relationship is referred to as ________.

Answer 4

amensalism

Question 5

4) When one species feeds on another prey species, typically killing it, the relationship between
the two interacting species is referred to as ________.

Answer 5

predation

Question 6

5) When individuals of two species interact, the nature of the interaction can be classified
qualitatively as positive, negative, or ________.

Answer 6

neutral

Question 7

6) ________ occurs when two species undergo reciprocal evolutionary change through natural
selection

Answer 7

coevolution

Question 8

7) Under certain conditions, ________ fungi live in the roots of many species of plants and have
a mutually beneficial relationship with the plants.

Answer 8

mycorrhizal

Question 9

8) The process in which a network of species undergoes reciprocal evolutionary change through
natural selection is referred to as ________.

Answer 9

diffuse coevolution

Question 10

9) The range of physical and chemical conditions under which each species can persist (survive
and reproduce) and the array of essential resources it utilizes are referred to as its ecological
________.

Answer 10

niche

Question 11

1) 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. The relationship is referred to as
A) amensalism.
B) comensalism.
C) competition.
D) parasitoidism.

Answer 11

B) comensalism.

Question 12

2) When the relationship between two interacting species is detrimental to the populations of
both species, the interaction is referred to as
A) parasitism.
B) mutualism.
C) competition.
D) amensalism.

Answer 12

C) competition

Question 13

3) As the population of a predator increases, the
A) population of the prey species decreases.
B) birthrate of the prey species increases.
C) mortality rate of the prey species decreases.
D) proportion of the prey population that is captured and consumed decreases

Answer 13

A) population of the prey species decreases

Question 14

4) When a species of bird preys upon the seeds of a plant and favors the smallest seeds,
A) the prey species functions as an agent of natural selection on the predator.
B) natural selection favors individual plants that produce the largest seeds.
C) the plants compensate for their losses by producing proportionately more smaller seeds.
D) the bird species is unaffected when directional selection favors plants that produce the largest
seeds.

Answer 14

B) natural selection favors individual plants that produce the largest seeds.

Question 15

5) Mycorrhizal fungi have a mutually beneficial relationship with plants in environments with
soils that
A) are saturated with water.
B) have a high clay content.
C) are acidic.
D) are low in nutrients

Answer 15

D) are low in nutrients.

Question 16

6) In most plant-pollinator interactions, plants species are pollinated by
A) one animal species, and each animal species pollinates one plant species.
B) one animal species, and each animal species pollinates multiple plant species.
C) multiple animal species, and each animal species pollinates one plant species.
D) multiple animal species, and each animal species pollinates multiple plant species.

Answer 16

D) multiple animal species, and each animal species pollinates multiple plant species.

Question 17

7) Two species of cattail (Typha) live in shallow water along the shoreline of ponds. Although T.
agustifolia can live by itself in water 0—20 cm deep, in the presence of T. latifolia, it occurs only
in water > 20 cm deep, whereas T. latifolia occurs in shallower water. In this example, T.
agustifolia is limited by competition exploiting its
A) ecological niche.
B) fundamental niche.
C) realized niche.
D) physiological niche.

Answer 17

C) realized niche.

Question 18

1) The flower of an orchid species is pollinated by a species of wasp that is deceived by the
orchid into thinking it is mating with another wasp.

Answer 18

true

Question 19

2) Predation always has a negative effect on the individual prey

Answer 19

true

Question 20

3) In a parasitic relationship between two species, the host species usually dies

Answer 20

false

Question 21

4) Parasitoidism is a form of mutualism

Answer 21

false

Question 22

5) When the population size of a prey species increases, the birthrate of a predator species should also increase

Answer 22

true

Question 23

6) The interaction between two species usually influences all individuals within the respective
populations equally.

Answer 23

false

Question 24

7) The relationship between nectar-producing flowers and nectar-feeding birds is a mutually
beneficial interaction.

Answer 24

true

Question 25

8) Species having wide geographic distributions generally encounter a broader range of physical
environmental conditions than species whose distribution is more restricted.

Answer 25

true

Question 26

9) Most interspecific interactions are exclusive, involving only two species.

Answer 26

false

Question 27

10) An organism’s realized niche is always smaller than its fundamental niche.

Answer 27

false

Question 28

11) Adaptive radiation can result from divergent adaptations to avoid predators.

Answer 28

true