Question 1

In Figure 8.13a,the percentage of herbivory between Azteca spp.and Myrmelachista schumanni in ant exclusions _______.

Accepted Answer

The text states that "The percentage of herbivory by A. spp. was roughly 2% in treatment plots and roughly 1.5% in exclusion plots. In contrast, percentage of herbivory for M. schumanni was nearly 1% in exclusion plots and roughly 3% in control plots." This indicates that the herbivory by M. schumanni was nearly three times greater than that of A. spp. in the control plots.

Question 2

An __________ is a finely branched intracellular cluster of fungi found in plant host cells.

Accepted Answer

An arbuscule is a finely branched intracellular cluster of fungi found in plant host cells. Ectomycorrhiza is a type of mycorrhiza in which the fungal hyphae remain outside the plant cells, while epiphyte is a plant that grows non-parasitically on another plant and derives its moisture and nutrients from the air, rain, and sometimes from debris accumulating around it. Ectosymbiont is a general term for any organism that lives outside another organism but has a mutually beneficial relationship with it.

Question 3

About _______% of flowering plants possess morphological features that serve to disperse seeds.

Accepted Answer

The answer of About _______% of flowering plants possess morphological...

Question 4

A bird feeds on the fruit of a plant.The bird will later regurgitate the seed.However,in the process of digesting the fruit and regurgitating the seed,the embryo is made non-viable.This is ___________.

Accepted Answer

Although the bird is dispersing the seeds, the fact that the embryo is made non-viable means that the plant is not actually benefiting from this relationship. Therefore, it cannot be considered a mutualism.

Question 5

__________ are mutualisms formed between plant root tissue and fungi.

Accepted Answer

Mycorrhiza is a mutualism formed between plant root tissue and fungi. The fungi help the plant absorb water and nutrients, while the plant provides the fungi with carbohydrates. Cruciferae is a family of plants, and arbuscular ectobiota is not a recognized term in biology.

Question 6

You are working on a research project in a garden and notice that many different insect species visit the same species of plant in the garden.All of the insects appear to be collecting nectar and pollen.This is likely because ________.

Accepted Answer

The fact that many different insect species are visiting the same plant indicates that it is being visited by generalist pollinators rather than specialized pollinators or ultraspecialists. The plant likely has a lot of nectar and pollen, making it an attractive resource for many different types of insects.

Question 7

You might expect the evolution of specialized animal pollinators and specialized flowers because ______________.

Accepted Answer

Specialized pollinators are more likely to effectively transfer pollen between conspecifics, reducing the chance of cross-pollination with other species, which can enhance the reproductive success of the plant.

Question 8

According to the classic study by de Wit et al.(1966),soybeans were grown in mixtures with a grass.Mixtures either received mineral nitrogen,were inoculated with Rhizobium,or both.The results of this experiment showed what?

Accepted Answer

The study found that in fertilized soil, the grass outcompetes the soybeans regardless of Rhizobium presence. However, in nitrogen-deficient soil with Rhizobium presence, soybeans had a greater yield and eventually outcompeted the grass. This indicates that the presence of Rhizobium can have a significant effect on plant growth in nitrogen-deficient environments.

Question 9

________ are found in roughly two-thirds of all plant species.

Accepted Answer

Arbuscular mycorrhizas are the most common type of mycorrhizal symbiosis found in roughly two-thirds of all plant species.

Question 10

Bacteria that are found in the root nodules of most leguminous plants and are responsible for fixing nitrogen are known as ______________.

Accepted Answer

Rhizobia are specifically adapted bacteria that form symbiotic relationships with leguminous plants, residing in the root nodules and fixing atmospheric nitrogen into a form usable by the plant. Arbuscules are a type of fungal structure that forms mutualistic relationships with many plant species, but they do not fix nitrogen. Parasitic fungi are not involved in nitrogen fixation in plants. Option D is incorrect because there is a specific term for these bacteria, which is rhizobia.

Quiz 8: Molecular and Evolutionary Ecology