Chapter 15 Mutualism

Question 1

Corals coexist with a type of algae called zooxanthellae. Without the algae producing sugars by photosynthesis, the coral polyps (animals) could not survive. This type of relationship would be called ______.

Answer 1

obligate mutualism

Question 2

Eukaryotic cells have mitochondria that were likely once separate organisms that evolved into a(n) _____ relationship, and later advanced to the point where both organisms depended upon each other for survival.

Answer 2

mutualistic

Question 3

Which of the following can be involved in mutualistic relationships with plants?

Answer 3

Animals

Fungi

Bacteria

Question 4

Mychorrhizae appear ______ in the evolution of ______ plants.

Answer 4

early; terrestrial

Question 5

When the mycorrhizal fungus produces exchange sites between plant and fungus, hyphae or fungal filaments, these are called 
 mycorrhizal fungi (AMF)

Answer 5

arbuscular

Question 6

Match the term with the best definition.

mutualism
facultative mutualism
obligate mutualism

Answer 6

Interactions between individuals of different species that are mutually beneficial.

While the interaction between species is beneficial, it’s not necessary for survival.

Interaction between two species where survival depends on the interaction.

Question 7

The scientist credited for recognizing that mycorrhizae involve a mutualistic relationship between plants and fungi is named Albert B. ______

Answer 7

frank

Question 8

Work done by Lynn Margulis and colleagues suggest that ______ were originally mutualistic partners with eukaryotic cells, and later became organelles.

Answer 8

mitochondria and chloroplasts

Question 9

Mycorrhizae are important to plants because they increase ______.

Answer 9

the plant’s access to nutrients such as nitrogen and water

Question 10

Plants may receive benefits from mutualism, including ______.

Answer 10

gaining access to soil nutrients

Question 11

Which of the following is true concerning mycorrhizae?

Answer 11

There is a mutualistic relationship between fungi and plants.

Question 12

Mycorrhizae appear in the fossil record around _______ years ago.

Answer 12

400 million

Question 13

In the graph shown, the blue (top) and green (bottom) lines show grass species grown with and without mycorrhizae. The higher water potential shown “with mycorrohizae” may be due to greater plant root growth resulting from greater access to the nutrient _______ provided by the fungi.

Answer 13

phosphorus

Question 14

The image labeled B is an example of what specific type of mycorrhizal fungus?

Answer 14

Ectomycorrhizae (ECM)

Question 15

In an experiment done with red clover, Kay Hardie grew mycorrhizal and nonmycorrhizal fungi in the presence of unlimited nutrient availability. What were the results of the experiments?

Answer 15

Mycorrhizal clover had higher rates of transpiration than nonmycorrhizal clover.

Question 16

Mycorrhizal relationships were first described by ______.

Answer 16

Albert Frank

Question 17

Which of the following is true concerning condition that may affect the level of mutualism between mycorrhizae and their host plants?

Answer 17

Plants release more soluble carbohydrates when they grow in nutrient-poor soils.

Question 18

Which of the following is not a nutrient that mycorrhizae help plants to obtain?

Answer 18

sugar

Question 19

In the first phase of Nancy Johnson’s work on the effects of soil fertilization on mycorrhizae, unfertilized soil was shown to support higher densities of ______ mycorrhizal fungal species, while fertilized soil supported higher densities of one main species. (Enter a number)

Answer 19

3

Question 20

Fungi that are closely associated with the roots of some plants are called
fungi. They are in a mutualistic relationship with the plant.

Answer 20

mycorrhizal

Question 21

Why were mycorrhizal fungi from both unfertilized and fertilized soil used in the experiment depicted?

Answer 21

The characteristics of mycorrhizae from unfertilized soil and fertilized soil might be different.

Question 22

In the graph shown, the blue (top) and green (bottom) lines show grass species grown with and without mycorrhizae. Which of the following is true?

Answer 22

Grass grown with mycorrhizae had higher leaf water potentials than those grown without.

Question 23

In an experiment done with red clover, Kay Hardie grew mycorrhizal and nonmycorrhizal fungi in the presence of unlimited nutrient availability. What were the results of the experiments?

Answer 23

Results indicated a direct role of mycorrhizae in the water relations of plants.

Mycorrhizal red clover had higher root:shoot ratios than nonmycorrhizal red clover.

Question 24

In a “less mutualistic” relationship between a plant and mycorrhizal fungus, the fungus would receive a(n) _____ or greater quantity of photosynthetic product in trade for delivery of a lower quantity of nutrient

Answer 24

equal

Question 25

In the first phase of Nancy Johnson's work on the effects of soil fertilization on mycorrhizae, ______.

Answer 25

soil fertilization affected the fungal species present

Question 26

In the greenhouse studies performed by Nancy Johnson, Andropogon grown with mycorrhizae, nitrogen, and ______ had the highest production of flowers.

Answer 26

phosphorus

Question 27

The diagram shown depicts an experimental design discussed in the chapter. What was this experiment trying to determine?

Answer 27

the long-term effects of fertilization on mycorrhizal fungi and plants

Question 28

True or false: Fertilized soil selects for less mutualistic mycorrhizal fungi.

Answer 28

true Fertilization of the soil allows the plants to not rely on their relationship with fungi as much.

Question 29

The results of Johnson's experiments on soil fertilization, mycorrhizae, and plant growth support the ______ model, which proposes that the availability of underground resources and aboveground resources controls plant allocation to roots, shoots, leaves, and mycorrhizae.

Answer 29

functional equilibrium

Question 30

In the greenhouse studies performed by Nancy Johnson, Andropogon (big bluestem grass) with mycorrhizae ______.

Answer 30

grew to a larger size regardless of soil nutrient levels

Question 31

The results of Johnson's study of mycorrhizae and soil nutrient levels showed that ______.

Answer 31

plants receive more benefit from mycorrhizae in unfertilized soil

Question 32

Acacia ants ______.

Answer 32

are highly aggressive defenders of the acacia plants

Question 33

Which of the following is not a characteristic of the swollen thorn acacia?

Answer 33

It produces leaves only during the spring and summer. CHARACTERISTICS - It produces Beltian bodies that provide oils for resident ants. It produces nectaries that are sources of sugars for resident ants. It has enlarged thorns that act as living space for ants.

Question 34

The results of Johnson's study of mycorrhizae and nutrient availability ______.

Answer 34

support the functional equilibrium model suggest that plants growing in fertilized soil will allocate less energy to mycorrhizae

Question 35

Acacia ants guard the acacia tree and ______.

Answer 35

lay eggs in the thorn of the tree

Question 36

Janzen's experiments on acacia ants and plant mutualism showed ants ______.

Answer 36

significantly improved plant performance

Question 37

Acacia performance is greater when acacia ants are present. When ants are absent, there tend to be ______ herbivorous insects on the plants than when the ants are present.

Answer 37

more

Question 38

Pseudomyrmex spp. (acacia ants) ______.

Answer 38

have good vision are fast, agile runners

Question 39

Match the Acacia resource with the benefit it provides the acacia ant. Beltian bodies Thorns Foliar nectaries

Answer 39

Source of oils and proteins Living space Source of sugars and liquids

Question 40

True or false: Swollen thorn acacias are only involved in one mutualistic relationship.

Answer 40

False

Question 41

Acacia ants rely on acacia plants for food and shelter, and the plants rely on the ants for aggressive protection from herbivores and other vegetation. This relationship is called ______ mutualism from the perspective of the ant.

Answer 41

obligate

Question 42

The scientists who investigated the possible conflicts between mutualists of the swollen thorn acacia are Nigel Raine, Pat Willmer, and Graham _____

Answer 42

stone

Question 43

Janzen's experiments on acacia ants and plant mutualism showed ______.

Answer 43

sucker survival was significantly higher in the presence of ants

Question 44

Which is one way that competition between pollinators and acacia ant is reduced?

Answer 44

Flowers occur on older shoots that ants avoid.

Question 45

Increased plant performance of acacias with ants may be due to ______.

Answer 45

less damage done by herbivorous insects

Question 46

Raine, Willmer, and Stone showed that new and older shoots on an acacia plant _______.

Answer 46

can be close together

Question 47

Match the mutualistic organism with its benefit for the swollen thorn acacias. acacia ant bees mycorrhizae bacteria

Answer 47

Drives away herbivorous insects from the acacia plant Pollinate the acacia plant Increase nutrient uptake from the soil into the plant Allow for nitrogen fixation

Question 48

Extrafloral nectaries ______.

Answer 48

produce nectar and are found outside of the flower

Question 49

The researchers who studied the potential conflicts between mutualists of swollen thorn acacias were named ______.

Answer 49

Raine, Willmer, and Stone

Question 50

Which of the following is incorrect?

Answer 50

Aspen sunflowers provide living spaces for mutualistic ants. CORRECT - Swollen thorn acacias provide lipids to ants via Beltian bodies. Swollen thorn acacias provide living spaces for mutualistic ants. Aspen sunflowers provide sucrose to ants via extrafloral nectaries. Swollen thorn acacias provide sucrose to ants via nectaries.

Question 51

______ shoots on acacia plants produce flowers. Foliar nectaries and Beltian bodies are found on ______ shoots.

Answer 51

Older; new

Question 52

Because ants associated with the aspen sunflower can also tend aphids on other _______ species as well as collect nectar from other flower species, they are considered to be facultative mutualist

Answer 52

plant

Question 53

Raine, Willmer, and Stone found that in the acacia plant, new inflorescences lack a potential ant attractant (nectar), while they do contain a chemical ______ that deters ants

Answer 53

repellant

Question 54

Inouye and Taylor suggested that ants associated with the aspen sunflower protect the flower's _____ from predators.

Answer 54

seeds

Question 55

Nectar-producing structures that are outside of the flowers are called ______ nectaries

Answer 55

extrafloral

Question 56

The graph indicates ______.

Answer 56

the presence of ants reduces seed predation on aspen sunflowers

Question 57

Both the extrafloral nectaries of the aspen sunflower and a similar structure in the swollen thorn acacia provide the sugar called _______ along with amino acids, to ants.

Answer 57

sucrose

Question 58

Aspen sunflower buds are vulnerable to late spring ______, which may keep the relationship between the sunflower and ants facultative.

Answer 58

frosts

Question 59

On an aspen sunflower, what structure is the sole source for sucrose?

Answer 59

extrafloral nectaries

Question 60

Like mycorrhizal fungi, corals receive ______ from zooxanthellae.

Answer 60

organic nutrients

Question 61

Ants on aspen sunflower can protect the sunflower seeds from predation by ______.

Answer 61

certain fly species certain moth species

Question 62

Which of the following is correct regarding the relationship between corals and zooxanthellae?

Answer 62

Zooxanthellae are induced to release nutrients when they receive chemical signals from corals.

Question 63

When Inouye and Taylor removed ants from the aspen sunflower, ______.

Answer 63

there was more seed predation

Question 64

Zooxanthellae fix carbon through the process of ______. Approximately ______ of this carbon is used by its coral partner.

Answer 64

photosynthesis; 90–99%

Question 65

Which of the following is incorrect?

Answer 65

Corals produce ammonium through the process of photosynthesis. CORRECT - Ammonium is a waste product of protein metabolism in corals. Corals that harbor zooxanthellae do not excrete significant amounts of ammonium. Zooxanthellae absorb ammonium from seawater. Corals that do not harbor zooxanthellae continuously excrete ammonium into their environment.

Question 66

Spring frosts may be beneficial to aspen sunflowers regardless of whether ants are present. What is the benefit to the sunflower that frosts provide?

Answer 66

Some seed predators have no place to lay their eggs.

Question 67

Zooxanthellae receive ______ from corals.

Answer 67

nutrients

Question 68

When certain crab species protect corals from sea star predation, and the crabs in turn receive food and shelter, this is an example of ______.

Answer 68

obligate mutualism

Question 69

Corals induce zooxanthellae to release organic nutrients by ______.

Answer 69

releasing chemicals that change the permeability of the zooxanthellae membrane

Question 70

The researcher who studied the efficacy of crustaceans to repel sea star attacks on corals is ______.

Answer 70

glynn

Question 71

Compared to most unicellular algae, zooxanthellae produce fixed carbon at ______.

Answer 71

a much higher rate than other nutrients

Question 72

In its mutualistic relationship with corals, zooxanthellae seem to benefit most by the acquisition of higher levels of _____ than they would normally have access to.

Answer 72

nutrients or nitrogen

Question 73

True or false: The only benefit corals receive from their mutualistic relationship with crabs is protection from large predators.

Answer 73

false Coral tissues are also healthier in the presence of crabs

Question 74

In the mutualistic relationship between crabs and corals, how do the crabs provide protection to the corals?

Answer 74

attack the sea stars spines and tube feet

Question 75

Corals provide ______ for their crustacean partners.

Answer 75

shelter mucus high in lipid content

Question 76

The scientist who showed that removing crabs from their coral partners resulted in greater tissue death in the corals is named John ______

Answer 76

stimson

Question 77

In the studies done by Stimson, it was determined that _____.

Answer 77

corals that harbor crabs produce more fat bodies

Question 78

Keeler's approach suggests that for a population to be mutualistic, the fitness of ______ mutualists must be greater than the fitness of unsuccessful mutualists or ______.

Answer 78

successful nonmutualists

Question 79

In Keeler's equation, q represents the ______.

Answer 79

proportion of the population that are unsuccessful mutualists

Question 80

In the presence of crabs, coral tissues are ______. They show less death in the deep axils of their branches.

Answer 80

healthier

Question 81

Keeler predicts that mutualism should persist in a population when the ______.

Answer 81

fitness of successful and unsuccessful mutualists exceeds the fitness of nonmutualists

Question 82

Corals contain large quantities of lipids, much of which is released with the ______ that it exuded onto the coral surface.

Answer 82

mucus

Question 83

In the presence of crabs, corals produce more | _____ which act as a food source for the crabs

Answer 83

fat bodies

Question 84

Keeler's approach to representing the costs and benefits of mutualism includes three types of mutualists. Match the type of mutualist with its description. successful unsuccessful nonmutualist

Answer 84

Give and receive measurable benefits to another organism. Give benefits to another organism but do not receive benefits themselves. Do not give or receive benefits from a partner organism.

Question 85

(H)(1 − A)(1 − D) − IA + ID is the selective coefficient for ______.

Answer 85

a successful mutualist

Question 86

In Keeler's equation for the fitness of mutualists, wmu represents the ______.

Answer 86

fitness of unsuccessful mutualists

Question 87

Using Keeler's selective coefficients to describe the mutualism between ants and plants, D is equal to ______.

Answer 87

protection provided to plant tissues by other defenses, such as thorns

Question 88

According to Keeler, mutualism persists between Cape Buffaloes and cattle egrets because the fitness of ______.

Answer 88

Cape buffaloes and egrets that are involved in mutualism is greater than those organisms that are nonmutualistic

Question 89

Keeler's model suggests that ______.

Answer 89

plants in a shady forest should be less likely to invest in attracting ants

Question 90

H(1 − D) + ID is the selective coefficient for ______.

Answer 90

a nonmutualist

Question 91

Honey badgers provide what service to honeyguide birds?

Answer 91

They can open bees' nests to access honey.

Question 92

Using Keeler's selective coefficients to describe the mutualism between ants and plants, A is equal to amount of ______.

Answer 92

herbivory prevented by ants

Question 93

Which of the following is not one of the researchers who studied the mutualism between honeyguides and humans?

Answer 93

Keeler CORRECT - Reyer Isack

Question 94

In Africa, the Boran people are guided to bee nests by the greater ______ These animals in turn receive access to the bee nest.

Answer 94

honeyguide

Question 95

While following the honeyguide to a bee nest, the human ______.

Answer 95

makes noise to "keep the bird interested"

Question 96

Sunflowers that are subject to high levels of damage from ______ are more likely to invest in nectar and nectaries that attract ants for protection.

Answer 96

herbivores

Question 97

The mutualistic association between humans and honeyguides may have evolved from an earlier association of the bird with the honey ______

Answer 97

badger

Question 98

The mutualistic relationship between humans and honeyguides was studied by Isack and ____

Answer 98

reyer

Question 99

What benefit do honeyguides gain in their relationship with humans?

Answer 99

access to bee nests containing food

Question 100

The middle graph indicates that as the distance to a bee's nest decreases the distances between stops ______.

Answer 100

decrease

Question 101

The typical behavior pattern shown by the greater honeyguide begins by the ______.

Answer 101

honeyguide flying close to the human and calling

Question 102

What information do the Boran receive from honeyguides?

Answer 102

direction to the bee nest notice of arrival at the nest distance to the nest

Question 103

When a honeyguide arrives at a bee nest, it makes a few indication calls and then remains _____

Answer 103

silent

Question 104

The top graph indicates that if a bee nest is far from the honeyguides' current location ______.

Answer 104

honeyguide stays in sight of the human for a longer period of time

Question 105

Honeyguides alert honey gathers to information on the distance to a bee nest, the ______ the human must travel to arrive at the nest, and notification of when they have arrived at the bee nest.

Answer 105

direction

Question 106

When a honeyguide is close to a bee nest, it will ______.

Answer 106

increase the frequency of the guiding call