Chapter 31 Mastering Bio

Which of the following ecological roles is/are played by at least some fungi?

-Decomposition -Predation

Arrange the following in order from largest to smallest, assuming that they all come from the same fungus. 1. basidiocarp 2. basidium 3. basidiospore 4. mycelium 5. gill

4 → 1 → 5 → 2 → 3

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 meters below the soil surface.

A

Cup fungi are in the phylum _____.

Ascomycota

Plasmogamy is indicated by the letter _____.

B (fusion of cytoplasm)

Where does meiosis occur in a mushroom?

Basidia

The process indicated by the letter _____ produces a diploid structure.

C

Refer to Figure A. Which of the following results would support Simard et al.'s (1997) hypothesis that fungi can move carbon from one plant to another? [Hypothesis: Sugars made by one plant during photosynthesis can travel through a mycorrhizal fungus and be incorporated into the tissues of another plant.]

Carbon-14 is found in the Douglas fir seedling's tissues and carbon-13 in the birch

On the graphs below, the x-axis labels indicate the number and identity of AMF species (bar 0 = no fungi; bars A-D = individual AMF species; bar A+B+C+D = all AMF species together). The y-axis indicates the amount (grams) of plant biomass for the species shown in italics above each graph. Based on the graphs in the figure above, which of the following plant species is most likely NOT to form mycorrhizal associations?

Carex flacca (graph a)

You observe the gametes of a fungal species under the microscope and realize that they resemble animal sperm. To which of the following group does the fungus belong?

Chytrids

Fungi form mutualistic relationships with plants and animals. Which of the following is an example of such a relationship?

Endophytes in leaves produce toxins that deter herbivores. Fungi can help increase drought tolerance in plants Fungi help break down plant material in the guts of grazing mammals. Fungi help break down wood in the guts of termites. (All of the above.)

True or false? In most fungi, fertilization is complete after the cells fuse together.

False

Which of the following is a difference between plants and fungi?

Fungi are heterotrophic, and plants are autotrophic.

Why are mycorrhizal fungi superior to plants at acquiring mineral nutrition from the soil?

Fungi secrete extracellular enzymes that can break down large molecules.

Almost all of the members of this phylum form arbuscular mycorrhizae in a mutualistic partnership with plants.

Glomeromycota

Which of the following events occurs first in the development of a spore into a mature mushroom?

Hyphae are produced by mitosis

Select the correct statement(s) about the origin of fungi.

Multicellularity probably arose independently in fungi and animals.

Which structure allows the growing mushroom to nourish itself?

Mycelium

Which structure is not directly involved in the reproduction of at least one major group of fungi?

Mycelium

Which of the following best describes the physical relationship of the partners involved in lichens?

Photosynthetic cells are surrounded by fungal hyphae.

Which term describes the fusion of cytoplasm from two individuals?

Plasmogamy

Fungi have an extremely high surface-area-to-volume ratio. What is the advantage of this to an organism that gets most of its nutrition through absorption?

The larger surface area allows for more material to be transported through the cell membrane.

In fungi, haploid hyphae fuse to produce dikaryotic and then diploid nuclei, only to restore the haploid condition by meiosis before the growth of new hyphae. What is the significance of a transient diploid state in fungi?

These sexual processes generate genetic variation.

True or false? Most of the cells in a mushroom contain haploid nuclei.

True

Fungi obtain nutrients through _____.

absorption

Deuteromycetes _____.

are the group of fungi that have, at present, no known sexual stage

The multicellular condition of animals and fungi seems to have arisen _____.

by convergent evolution

Most fungi are _____.

decomposers

Karyogamy produces a _____.

diploid zygote

When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter?

fungal enzymes

The functional significance of porous septa in certain fungal hyphae is most similar to that represented by which pair of structures in animal cells and plant cells, respectively?

gap junctions - plasmodesmata

Fungi produce _____ spores.

haploid

An important example of interaction between fungi and certain other organisms is mycorrhizae, in which the fungal partners _____.

help plants take up nutrients and water

All fungi share which of the following characteristics?

heterotrophic

The body of most fungi consists of threadlike _____, which form a network called a _____.

hyphae ... mycelium

What sexual processes in fungi generate genetic variation?

karyogamy and meiosis

If haustoria from the fungal partner were to appear within the photosynthetic partner of a lichen, and if the growth rate of the photosynthetic partner consequently slowed substantially, then this would support the claim that _____.

lichens are not purely mutualistic relationships

Basidia produce spores by a process known as _____.

meiosis

Some fungal species can kill herbivores while feeding off of sugars from its plant host. What type of relationship does this fungus have with its host?

mutualistic

If all fungi in an environment that perform decomposition were to suddenly die, then which group of organisms should benefit most, due to the fact that their fungal competitors have been removed?

prokaryotes

In most fungi, karyogamy does not immediately follow plasmogamy, which consequently _____.

results in heterokaryotic or dikaryotic cells

From the human perspective, which of the following kinds of fungi would be considered the least useful or beneficial?

rusts

Fungi of the phylum Ascomycota are recognized on the basis of their production of _____ during sexual reproduction.

saclike structures

A billionaire buys a sterile volcanic island that recently emerged from the sea. To speed the arrival of conditions necessary for plant growth, the billionaire might be advised to aerially sow what over the island?

soredia

Fungi release digestive enzymes into their _____.

surroundings

Which of these contains two haploid nuclei?

the heterokaryotic stage of the fungal life cycle