Ecology Ch. 15

Which of the following is true concerning mycorrhizae? There is a mutualistic relationship between fungi and plants.

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

Corals provide shelter, mucus high in lipid content for their crustacean partners.

Match the mutualistic organism with its function:

Acacia ant – drives away herbivorous insects from the acacia plant

Bees – pollinate the acacia plant

Mycorrhizae – increase nutrient uptake from the soil into the plant

Bacteria – allow for nitrogen fixation

Which of the following is NOT a nutrient mycorrhizae help plants to obtain? Sugar

Does obtain: phosphorus, zinc, nitrogen, copper

Match the term on the left with the best definition from the right.

Mutualism – interaction between individuals of different species that are mutually beneficial

Facultative mutualism – while the interaction between species is beneficial, it’s not necessary for survival

Obligate mutualism – interaction between two species where survival depends on the interaction

What information do the Boran receive from honeyguides? Notice of arrival at the nest; direction to the bee nest; distance to the nest

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

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

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

Which of the following can be involved in mutualistic relationships with plants? Bacteria, animals, fungi

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

In Africa, the Boran are guided to bee nests by honeyguides. These animals in turn receive access to the bee nests.

Match the plant resource with the benefit it provides the acacia ant.

Beltian bodies – source of oils and proteins

Thorns – living space

Foliar nectaries – source of sugars and liquids

Pseudomyrmex spp. (acacia ants): are fast, agile runners; have good vision

While following the honeyguide to a bee nest, the human makes noise to let the bird know he/she is “interested”

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

Keeler’s approach to representing the costs and benefits of mutualism includes 3 types of mutualists. Match the type of mutualist with its description.

Successful – give and receive measurable benefits to another organism

Unsuccessful – give benefits to another organism but do not receive benefits themselves

Nonmutualist – do not give or receive benefits from a partner organism

When Inouye and Taylor removed ants from the aspen sunflower, there was more seed predation

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 obligate mutualism from the perspective of the ant.

According to Keeler, mutualism persists between Cape Buffaloes and cattle egrets because: the fitness of Cape Buffaloes and egrets that are involved in mutualism is greater than those organisms that are nonmutualistic

Ants on aspen sunflower can protect the sunflower seeds from predation by: certain moth species; certain fly species

Like mycorrhizal fungi, corals receive organic nutrients from zooxanthellae

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

Eukaryotic cells have mitochondria that were likely once separate organisms involved in an obligate mutualistic relationship, where both organisms depended upon each other for survival

Plants may receive benefits from mutualism including: gaining access to soil nutrients

Acacia ants: are highly aggressive defenders of the acacia plants

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

The graph indicates: the presence of ants reduces seed predation on aspen sunflowers

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

Acacia ants: lay eggs in the thorn of the acacia plant

What information do the Boran receive from honeyguides? Direction to the bee nest; distance to the nest; notice of arrival at the nest

In the presence of crabs, coral produce more fat bodies, which act as a food source for the crabs

Extrafloral nectaries: produce nectar and are found outside of the flower

Inouye and Taylor suggested that ants associated with the aspen sunflower protect the flower’s seeds from predators

The results of Johnson’s study of mycorrhizae and nutrient availability: support the functional equilibrium model; suggest that plants growing in fertilized soil will allocate less energy to mycorrhizae

Honey badgers provide what service to honeyguide birds? They can open bees’ nests to access honey

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 her experiments? Removing fungal hyphae reduced rates of transpiration; results indicated a direct role of mycorrhizae in the water relations of plants

In Keeler’s equation, q is the proportion of the population that are unsuccessful mutualists

Which of the following is true concerning conditions that may affect the level of mutualism between mycorrhizae and their host plants? Plants release more soluble carbohydrates when they grow in nutrient-poor soils

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

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

The only benefit corals receive from their mutualistic relationship with crabs is protection from large predators. FALSE

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

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

Janzen’s experiments on acacia ants and plant mutualism showed: ants significantly improved plant performance

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

Which of the following is correct regarding the relationship between corals and zooxanthellae? Zooxanthellae are induced to release nutrients when they receive chemical signals from corals

Mychorrhizae appea early in the evolution of terrestrial plants

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

In a “less mutualistic” relationship between a plant and mycorrhizal fungus, the fungus would receive an equal or greater quantity of photosynthetic product in trade for delivery of a lower quantity of nutrients.

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

In Keeler’s equation for the fitness of mutualists, w_mu is: the fitness of unsuccessful mutualists

Why were mycorrhizal fungi from both unfertilized and fertilized soil used in the experiment depicted? The characteristics of mycorrhizae from unfertilized soil and fertilized soil might be different

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

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 three mycorrhizal fungal species, while fertilized soil supported higher densities of one main species.

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

The image shown depicts an experimental design discussed in the chapter. What was this experiment trying to determine? The long-term effects of fertilization on mycorrhizal fungi and plants

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

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

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

Zooxanthellae fix carbon through the process of photosynthesis. Approximately 90-99% of this carbon is used by its coral partner.

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

Using Keeler’s selective coefficients to describe the mutualism between ants and plants, A is equal to amount of herbivory prevented by ants

Fertilized soil selects for less mutualistic mycorrhizal fungi. TRUE

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

In the first phase of Nancy Johnson’s work on the effects of soil fertilization on mycorrhizae: soil fertilization affected the fungal species present

In the greenhouse studies performed by Nancy Johnson, Andropogon with mycorrhizae: grew to a larger size regardless of soil nutrient levels

Mycorrhizal relationships were first described by Albert Frank

The results of Johnson’s study of mycorrhizae and soil nutrient levels showed that plants receive more benefit from mycorrhizae in unfertilized soil