Question 1

Ug99 is a type of _____, and is a fungus (rust) that has decimated wheat crops across the globe.

Accepted Answer

Ug99 is a type of basidiomycete, which is a class of fungi. This particular rust fungus has caused significant damage to wheat crops worldwide due to its virulence and the difficulty in breeding wheat varieties resistant to it.

Question 2

On a hike through the forest, you notice a circle of "mushrooms," each with a stalk, cap, and gills on the underside of the cap. If you dig into the soil below the ring, which of the following might you find?

Accepted Answer

The answer of On a hike through the forest, you...

Question 3

Crossing over during mitosis increases genetic diversity during:

Accepted Answer

Parasexuality involves genetic recombination similar to crossing over, which can occur during mitosis, increasing genetic diversity without sexual reproduction.

Question 4

Which of the following statements is TRUE regarding the sexual life cycle of basidiomycetes?

Accepted Answer

The answer of Which of the following statements is TRUE...

Question 5

Which of the following is NOT a benefit of spore production in fungi?

Accepted Answer

This is the only option that does not describe a benefit of spore production in fungi. Option D is incorrect, as fungi tend to produce large numbers of spores, not small numbers.

Question 6

How is karyogamy different from plasmogamy?

Accepted Answer

Karyogamy is the fusion of nuclei, while plasmogamy is the fusion of cytoplasmic parts.

Question 7

Close observation of the fruiting bodies of cup fungi (ascomycetes) shows that when asci of cup fungi forcibly eject their spores up into the air, they tend do so in groups (i.e., many asci at once) instead of one at a time. Furthermore, spores released during one of these group events tend to go higher into the air than do spores released from a single ascus. This suggests that the simultaneous spore release by multiple asci is likely an adaptation that:

Accepted Answer

The fact that spores released during group events go higher into the air suggests that the adaptation of simultaneous spore release by multiple asci enhances the ability of spores to penetrate the layer of stagnant or unmoving air above the fruiting body. This would increase the likelihood of finding new habitats for successful colonization.

Question 8

Which of the following represents the CORRECT sequence of events in parasexual fungi that results in an increase in genetic diversity?

Accepted Answer

In parasexual fungi, the correct sequence for increasing genetic diversity starts with plasmogamy (fusion of cytoplasm from two different cells), followed by karyogamy (fusion of nuclei), then mitotic crossing over (exchange of genetic material during mitosis), and finally chromosome loss. This sequence allows for the combination and recombination of genetic material, increasing diversity.

Question 9

Which of the following represents the CORRECT order of events in fungal sexual reproduction starting from when hyphae of two different mating types grow together?

Accepted Answer

The correct sequence for fungal sexual reproduction is: plasmogamy (fusion of cytoplasm from two different mating types), leading to a heterokaryotic stage (nuclei from different types coexist without fusing), followed by karyogamy (fusion of nuclei), resulting in a zygote, which then undergoes meiosis to produce haploid spores. These spores disperse and grow into new haploid mycelia.

Question 10

In many groups of fungi, karyogamy and plasmogamy are separated in time and space. One potential advantage of this arrangement is that:

Accepted Answer

Separating karyogamy and plasmogamy in time and space allows fungi to mate and produce spores in different environments. For example, the plasmogamy (fusion of cytoplasm) may occur between two individuals in a nutrient-rich environment, while the karyogamy (fusion of nuclei) may occur when conditions are more favorable for spore production and dispersal. This separation allows fungi to adapt to changing environments and improve their chances of reproduction.

Question 11

Which of the following statements CORRECTLY describes a difference between sexual reproduction and parasexuality?

Accepted Answer

Crossing over occurs during mitosis in parasexual fungi, which is a process where genetic material is exchanged between non-sister chromatids of homologous chromosomes. This contrasts with sexually reproducing fungi, where crossing over occurs during meiosis, a key step in sexual reproduction that contributes to genetic diversity.

Question 12

What is the primary advantage of having multiple mating-type alleles?

Accepted Answer

Having multiple mating-type alleles increases the probability that two fungi encountering each other will have compatible mating types, leading to successful sexual reproduction.

Question 13

Your instructor gives you a sample from two different fruiting bodies-not the entire fruiting body. Which of the following characteristics differentiate whether one is an ascomycete and the other a basidiomycete?

Accepted Answer

Ascomycetes typically produce eight spores (ascospores) following meiosis, while basidiomycetes produce four spores (basidiospores).

Question 14

Consider the phylogeny (Fig. 34.15) below. Imagine that the trait "complex multicellular fruiting bodies" actually was present in the common ancestor indicated by the arrow. What would its presence in the common ancestor mean for the evolution of fruiting bodies in the group Dikarya?

Accepted Answer

If complex multicellular fruiting bodies were present in the common ancestor indicated by the arrow, but not in the Glomeromycetes, then the most likely scenario is that the trait was lost in this group. This means that the presence of complex multicellular fruiting bodies would have evolved independently in different lineages within the group Dikarya.

Question 15

Which of the arrows on the phylogeny indicates where the loss of flagella occurred?

Accepted Answer

The answer of Which of the arrows on the phylogeny...

Question 16

A researcher discovers a new species of fungi that forms hyphae, but not septa. This fungus also lacks multicellular fruiting bodies and does not appear to form either endomycorrhizae or ectomycorrhizae with plants. How should this fungus be classified?

Accepted Answer

Zygomycetes typically have coenocytic hyphae (lacking septa) and do not form multicellular fruiting bodies, which matches the description of the newly discovered fungus.

Question 17

Recall that glomeromycetes are fungi that can form symbiotic relationships (endomycorrhizae) with plants. Which of the following statements is also true of glomeromycetes?

Accepted Answer

The answer of Recall that glomeromycetes are fungi that can...

Question 18

The most recent common ancestor of animals and fungi was a multicellular aquatic organism.

Accepted Answer

The most recent common ancestor of animals and fungi is thought to have been a unicellular organism, not multicellular.

Question 19

How are the zygote and the dikaryotic stages of a fungal life cycle related?

Accepted Answer

The dikaryotic stage, characterized by two separate nuclei in one cell, precedes the formation of the zygote in many fungi. The zygote is formed when these two nuclei fuse in a process called karyogamy.

Question 20

Consider the phylogeny (Fig. 34.15) below. The group Dikarya has more species than all other taxa on the tree combined. Using only the information conveyed by the labeled phylogeny below, indicate which one of the following statements is a plausible explanation as to why this is so. Select all that apply.)

Accepted Answer

The answer of Consider the phylogeny (Fig. 34.15) below. The...

Quiz 34: Fungi: Structure, Function, and Diversity