1.Which of the following is NOT a characteristic of a fungus?
a. Cell walls made of chitin
b. A form of mitosis different from plants and animals
c. Ability to conduct photosynthesis
d. Filamentous structure
The correct answer is c—
A. Answer a is incorrect. The cell walls of fungi contain chitin.
The correct answer is c—
B. Answer b is incorrect. The form of mitosis in fungi is different from that in all other organisms.
The correct answer is c—Ability to conduct photosynthesis
C. Answer c is correct. Fungi are heterotrophs, not autotrophs.
The correct answer is c—
D. Answer d is incorrect. Fungi are composed of filamentous structures called hyphae.
2. A fungal cell that contains two genetically different nuclei would be classified as ______.
a. monokaryotic
b. bikaryotic
c. homokaryotic
d. heterokaryotic
The correct answer is d—
A. Answer a is incorrect. A monokaryotic cell would contain a single nucleus.
The correct answer is d—
B. Answer b is incorrect. This is not a term used to describe the number of nuclei in a cell, although dikaryon is.
The correct answer is d—
C. Answer c is incorrect. A homokaryotic cell would possess two genetically similar nuclei.
The correct answer is d—heterokaryotic
D. Answer d is correct.
3. Which of the following groups of fungi is NOT monophyletic?
a.Zygomycota
b.Basidiomycota
c.Glomeromycota
d.Ascomycota
The correct answer is a—Zygomycota
A. Answer a is correct. The Zygomycota is not believed to be monophyletic.
The correct answer is a—
B. Answer b is incorrect. The Basidiomycota is believed to be monophyletic.
The correct answer is a—
C. Answer c is incorrect. The Glomeromycota is believed to be monophyletic.
The correct answer is a—
D. Answer d is incorrect. The Ascomycota is believed to be monophyletic
4. Based on physical characteristics, the ______represent the most ancient phyla of fungi.
a.Basidiomycota
b.Zygomycota
c. Ascomycota
d.Chytridomycota
The correct answer is d—
A. Answer a is incorrect. Refer to Figure 31.6.
The correct answer is d—
B. Answer b is incorrect. Refer to Figure 31.6.
The correct answer is d—
C. Answer c is incorrect. Refer to Figure 31.6.
The correct answer is d—Chytridomycota
D. Answer d is correct. Chytridomycota possesses flagella and is aquatic.
5.Which of the following groups of fungi does not represent a true phylogenic relationship, but rather a classification due to a lack of scientific information?
a.Basidiomycota
b.Acomycota
c.Deuteromycetes
d.Glomeromycota
The correct answer is c—
A. Answer a is incorrect. Basidiomycota is a monophyletic group.
The correct answer is c—
B. Answer b is incorrect. Ascomycota is a monophyletic group.
The correct answer is c—Deuteromycetes
C. Answer c is correct. These are the “imperfect” fungi and species are placed into this group due to a lack of information regarding their method of sexual reproduction and evolutionary relationships.
The correct answer is c—
D. Answer d is incorrect. The Glomeromycota is a monophyletic group.
6. The early evolution of terrestrial plants was made possible by mycorrhizal relationships with the ______.
a.Zygomycetes
b.Glomeromycota
c.Ascomycota
d.Basidiomycota
The correct answer is b—
A. Answer a is incorrect. Zygomycota is not associated with mycorrhizae.
The correct answer is b—Glomeromycota
B. Answer b is correct. The Glomeromycota forms symbiotic relationships with plants.
The correct answer is b—
C. Answer c is incorrect. The Ascomycota is not associated with mycorrhizae.
The correct answer is b—
D. Answer d is incorrect. The Basidiomycota is not associated with mycorrhizae.
7. In a culture of hyphae of unknown origin you notice that the hyphae lack septa and that the fungi reproduce asexually by using clumps of erect stalks. However, at times sexual reproduction can be observed. To what group of fungi would you assign it?
a.Deuteromycetes
b.Basidiomycota
c. Ascomycota
d.Zygomycota
The correct answer is d—
A. Answer a is incorrect. Since you can observe a method of reproduction, this is not a member of the Deuteromycetes.
The correct answer is d—
B. Answer b is incorrect. Basidiomycota does not have these characteristics.
The correct answer is d—
C. Answer c is incorrect. Ascomycota does not have these characteristics.
The correct answer is d—Zygomycota
D. Answer d is correct. The stalks are called sporangiophores, and this culture is most likely a Zygomycota.
8.In a life cycle of a typical Basidiomycota, where would you expect to find a dikaryotic cell?
a.Primary mycelium
b.Secondary mycelium
c.In the basidiospores
d.In the zygote
The correct answer is b—
A. Answer a is incorrect. The primary mycelium is monokaryotic.
The correct answer is b—Secondary mycelium
B. Answer b is correct. This is the only dikaryotic stage of a Basidiomycota life cycle.
The correct answer is b—
C. Answer c is incorrect. The basidiospores are monokaryotic.
The correct answer is b—
D. Answer d is incorrect. The zygote is not dikaryotic.
9. Which of the following is correct regarding the yeast Saccharomyces cerevisiae?
a.It reproduces asexually by a process called budding.
b.It produces an ascocarp during reproduction.
c.It belongs in the group Deuteromycetes.
d.All of the above are correct.
The correct answer is a—It reproduces asexually by a process called budding.
A. Answer a is correct. S. cerevisiae primarily reproduces asexually.
The correct answer is a—
B. Answer b is incorrect. Although S. cerevisiae belongs to the ascocarps, it does not produce sexually.
The correct answer is a—
C. Answer c is incorrect. S. cerevisiae is an ascocarp.
The correct answer is a—
D. Answer d is incorrect. Only one of the answers is correct.
10. If biologists were to abandon the use of Deuteromycetes as a method of classification, to which phylum would the majority of the Deuteromycetes be assigned?
a.Ascomycota
b.Basidiomycota
c.Zygomycota
d.None of the above
The correct answer is a—Ascomycota
A. Answer a is correct. The majority of these fungi appear to have characteristics similar to those of the Ascomycota.
The correct answer is a—
B. Answer b is incorrect. Although some of these fungi may have characteristics similar to those of the Basidiomycota, the majority do not.
The correct answer is a—
C. Answer c is incorrect. Although some of these fungi may have characteristics similar to those of the Zygomycota, the majority do not.
The correct answer is a—
D. Answer d is incorrect. Answer a is correct.
11. Penicillium and Aspergillus are both classified as ______.
a.Basidiomycota
b.Deuteromycetes
c.Ascomycota
d.Zygomycota
The correct answer is b—
A. Answer a is incorrect. These genera are not assigned to the Basidiomycota.
The correct answer is b—Deuteromycetes
B. Answer b is correct. These genera are currently assigned with the Deuteromycetes.
The correct answer is b—
C. Answer c is incorrect. These genera are not currently assigned to the Ascomycota.
The correct answer is b—
D. Answer d is incorrect. These genera are not assigned to the Zygomycota.
12. Symbiotic relationships occur between the fungi and ______.
a.plants
b.bacteria
c.animals
d.all of the above
The correct answer is d—
A. Answer a is incorrect. Although fungi form symbiotic relationships with plants, this is not the only answer.
The correct answer is d—
B. Answer b is incorrect. Although fungi form symbiotic relationships with bacteria, this is not the only answer.
The correct answer is d—
C. Answer c is incorrect. Although fungi form symbiotic relationships with animals, this is not the only answer.
The correct answer is d—all of the above.
D. Answer d is correct. Fungi form symbiotic relationships with all of these groups.
13. A fungal relationship between a forest tree and a basidiomycete would most likely be classified as an example of ______.
a.parasitism only
b.an arbuscular mycorrhizae
c.ectomychorrhizae
d.a lichen
The correct answer is c—
A. Answer a is incorrect. The relationship could be a mycorrhizal relationship, which is mutually beneficial to both species.
The correct answer is c—
B. Answer b is incorrect. This form of mycorrhizae are associated with the Glomeromycetes.
The correct answer is c—ectomychorrhizae
C. Answer c is correct.
The correct answer is c—
D. Answer d is incorrect. Lichens represent relationships between fungi and algae or photosynthetic bacteria.
14. Symbiotic relationships between animals and fungi are focused on which of the following?
a.Protection from bacteria
b.Colonization of land
c.Protection from desiccation
d.Exchange of nutrients
The correct answer is d—
A. Answer a is incorrect. This is not the focus of fungal–animal symbiotic relationships.
The correct answer is d—
B. Answer b is incorrect. This is not the focus of fungal–animal symbiotic relationships, but was essential for plants.
The correct answer is d—
C. Answer c is incorrect. This is not the focus of fungal–animal symbiotic relationships.
The correct answer is d—Exchange of nutrients
D. Answer d is correct.
15. Which of the following species of fungi is not associated with diseases in humans?
a.Pneumocystis jiroveci
b.Aspergillus flavus
c.Candida albicans
d.Batrachochytrium dendrobatidis.
The correct answer is d—
A. Answer a is incorrect. P.jiroveci is known to cause pneumonia in AIDS patients.
The correct answer is d—
B. Answer b is incorrect. A. flavus is known to cause kidney damage.
The correct answer is d—
C. Answer c is incorrect. Candida albicans can cause oral or vaginal infections.
The correct answer is d—Batrachochytrium dendrobatidis
D. Answer d is correct. B. dendrobatidis is associated with skin infections and death in amphibians, specifically frogs.
Challenge Questions
1. Historically fungi have been classified as being more plantlike despite their lack of photosynthetic ability. Although we now know that fungi are more closely related to the animals than the plants, what characteristics would have initially led scientists to place them closer to the plants?
Answer—Fungi possess cell walls. Although thecomposition of these cell walls differs from that of the plants, cell walls are completely absent in animals. Fungi are also immobile (except for chytrids), and mobility is a key characteristic of the animals.
2. The importance of fungi in the evolution of terrestrial life is typically understated. Explain the importance of fungi in the colonization of land.
Answer—The mycorrhizal relationships between the fungi and plants allow plants to make use of nutrient poor soil. Without the colonization of land by plants, it is unlikely that animals would have diversified to the level they have achieved today. Lichens are important organisms in the colonization of land. Early land masses would have been composed primarily of barren rock, with little or no soil for plant colonization. As lichens colonize an area they begin the process of soil formation, which allows other plant species to move into the area.
3. Based on your understanding of fungi, why won’t antibiotics work in the treatment of a fungal infection?
Answer—Antibiotics are designed to combat prokaryotic organisms and fungi are eukaryotic. In addition, fungi possess a cell wall that has a different chemical constitution (chitin) from that of prokaryotes.
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Chapter 31