Deck 15: Mutualism

Question 1

Deep Check
Raine,Willmer,and Stone demonstrated that protection and pollination mutualism do not come into conflict on the swollen thorn acacia,Acacia hindsii,because
A) hindsii inflorescences contain a chemical ant repellent.
A) hindsii inflorescences lack nectar.

A) there is spatial separation of inflorescences and resources used by guarding ants.
B)
C)

Answer 1

D

Question 2

The "unsuccessful mutualists" in Kathleen Keeler's cost-benefit model of mutualism are those that

A) give benefits to their partner, but fail to receive benefits in return.
B) receive benefits from their partner, but fail to provide benefits in return.
C) neither give benefits to their partner, nor receive them in return.
D) fail to locate individuals of their mutualistic partner effectively.
E) locate mutualistic partners, but fail to overcome their defenses against colonization.

Answer 2

A

Question 3

Ants on the aspen sunflower,Helianthella quinquenervis,obtain sugars and amino acids by

A) collecting nectar from the sunflower's flowers.
B) collecting nectar from extrafloral nectaries.
C) tending aphids that extract plant sap.
D) extracting plant sap directly by piercing the sunflower stem.
E) All of the choices are correct.

Answer 3

B

Question 4

In experiments with the prairie grass Andropogon,root:shoot ratios proved to be

A) higher in plants grown in poor soils.
B) lower in plants grown in poor soils.
C) equal in plants grown in poor and rich soils.
D) higher in plants grown with mycorrhizae.
E) equal in plants grown with and without mycorrhizae.

Question 5

Crabs and shrimp associated with corals protect their hosts from

A) being dislodged from the substrate by currents.
B) predation by sea-stars.
C) predation by fishes.
D) attack by parasitic nematodes.
E) infection by pathogenic bacteria.

Question 6

Which of the following organisms are dependent on mutualisms for their persistence?

A) reef-building corals
B) bioluminescent fishes
C) bumblebees and hummingbirds
D) horses, elephants, and camels
E) All of the choices are correct.

Question 7

Mycorrhizal fungi (directly)help their plant partners acquire

A) sugars.
B) sunlight.
C) seed dispersal.
D) soil nutrients.
E) pollination.

Question 8

The interaction between honeyguide birds and the Boran people of Kenya

A) is an obligate mutualism.
B) is a facultative mutualism.
C) is exploitative, with humans benefiting but honeyguides exploited.
D) represents the only way a honeyguide can gain access to a beehive.
E) depends only on humans following birds, not on active communication by the birds.

Question 9

Ant-acacia trees provide several services to their mutualistic ant partners.These include

A) enlarged thorns to host ant colonies.
B) nectar from foliar nectaries.
C) nectar from floral nectaries.
D) All of the choices are correct.
E) Both enlarged thorns to host ant colonies and nectar from foliar nectaries.

Question 10

The major benefit obtained by aspen sunflower,Helianthella quinquenervis,from its ant mutualists is

A) reduced losses of seeds to seed predators.
B) reduced loss of leaf tissue to herbivorous insects.
C) more efficient extraction of soil nutrients.
D) more rapid growth early in the growing season.
E) improved attraction of pollinators.

Question 11

Mycorrhizal fungi acquire _________ from their plant partners.

A) sugars
B) soil nutrients
C) proteins and lipids
D) growth hormones
E) protection from consumers

Question 12

The enlarged thorns of swollen thorn acacias provide ants with

A) a source of sugar.
B) a source of protein.
C) a source of fats.
D) living space.
E) a habitat for their prey species.

Question 13

Soil fertilization should favor mycorrhizal fungi that are

A) less aggressive at obtaining sugars from their plant hosts.
B) more aggressive at obtaining sugars from their plant hosts.
C) more efficient at extracting inorganic nutrients from soils.
D) more efficient at extracting sugars from soils.
E) more efficient at extracting inorganic nutrients from plant root exudates.

Question 14

The major benefit obtained by zooxanthellae algal cells from their coral host is

A) protection from herbivores.
B) sugars.
C) phosphorus from coral wastes.
D) nitrogen from coral wastes.
E) temperature regulation.

Question 15

Which of the following is not a benefit provided by mutualistic crab and shrimp to the Pocillopora coral?

A) protection from predators
B) promotion of the health and integrity of coral tissue
C) source of lipids
D) both protection from predators and source of lipids
E) both promotion of the health and integrity of coral tissue and source of lipids

Question 16

An interaction between individuals of different species that benefit both partners is called

A) commensalism.
B) predation.
C) exploitation.
D) mutualism.
E) ammensalism.

Question 17

Nutrient poor soils should favor mycorrhizal fungi that are

A) less aggressive at obtaining sugars from their plant host.
B) more aggressive at obtaining sugars from their plant host.
C) more efficient at extracting inorganic nutrients from soil.
D) more efficient at extracting sugars from soil.
E) more efficient at extracting inorganic nutrients from plant root exudates.

Question 18

Which aspects of the biology of zooxanthellae are controlled by their coral hosts?

A) their cell wall chemistry
B) their population growth rate when free-living
C) the release of photosynthetic products from their cells
D) the rate at which they absorb sugars from their hosts
E) their mortality rate

Question 19

In Kathleen Keeler's cost-benefit model of mutualism,the condition for persistence of mutualists is pw_mw + qw_mu > w_nm.The parameters p and q represent the

A) cost and benefit of the mutualism.
B) fitness of successful and unsuccessful mutualists.
C) frequency of "mutualist" and "nonmutualist" alleles in the population.
D) proportion of successful and unsuccessful mutualists in the population.
E) amount of herbivore protection provided by ant and non-ant defenses.

Question 20

A calculated range of values that we estimate contains the true mean of a population with a known degree of certainty is called a

A) standard error.
B) standard deviation.
C) median.
D) Students t-value.
E) confidence interval.

Question 21

A cost-benefit model predicts that aspen sunflowers (Helianthella quinquenervis)in shady habitats should be less likely to attract ants than those living in sunny habitats.

Question 22

A mutualistic relationship in which either species can survive without its partner is called a ______________ mutualism.

Question 23

What is the 95% confidence interval for the Gila River sample of loach minnows given: mm,s = 6.2 mm,n = 50,and critical value of t = 2.01.

A) 56.2 mm + 1.77 mm
B) 56.2 mm $\pm$ 1.77 mm
C) 56.2 mm - 2.26 mm
D) 56.2 mm $\pm$ 0.25 mm
E) 56.2 mm + 0.25 mm

Question 24

Which of the following results,from research conducted by Nancy Johnson on big blue stem grass,suggested that mycorrhizal plants had greater access to nutrients?

A) root:shoot ratios were significantly lower in plants with mycorrhizae
B) root:shoot ratios were significantly higher in plants with mycorrhizae
C) root:shoot ratios were equal in plants with and without mycorrhizae
D) root:shoot ratios were highest in treatments without nitrogen supplements
E) root:shoot ratios were lowest in the treatment with nitrogen supplements

Question 25

The two most common types of mycorrhizal fungi are ___________ and ____________.

Question 26

Modified leaflet tips of bullshorn acacia that provide a food source for ants are called ___________.

Question 27

Which of the following statements is true regarding the control of coral over zooxanthellae?

A) Coral induces zooxanthellae to release organic compounds.
B) Coral controls the rate of zooxanthellae population growth.
C) Coral controls the population density of zooxanthellae.
D) Coral promotes unbalanced growth in zooxanthellae.
E) All of the choices are true.

Question 28

_____________ mutualism describes a relationship where species are so dependent on their mutualistic relationship they cannot live in its absence.

A) Obligate
B) Critical
C) Facultative
D) Dispensable
E) Essential

Question 29

The photosynthetic zooxanthellae associated with reef-building corals are members of the Phylum ___________.

Question 30

The presence of ant mutualists on bullshorn acacia reduces herbivore attack and increases acacia growth rate,but has little effect on acacia mortality rate.