Q1. Which of the following fungal groups is not monophyletic?
Correct Answer: (a)
Current molecular phylogenetic studies indicate that the traditional group Zygomycota is paraphyletic. It is currently being reorganized into several smaller monophyletic lineages and phyla.
Q2. 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?
Correct Answer: (d)
The lack of septa (coenocytic hyphae) is a primary morphological characteristic of the Zygomycota. They also typically produce asexual spores on stalks called sporangiophores.
Q3. A life cycle that alternates between a multicellular haploid generation and a multicellular diploid generation is seen in __________ and _________.
Correct Answer: (d)
A haplodiplontic life cycle, which involves an alternation between a multicellular haploid gametophyte and a multicellular diploid sporophyte, is found in all land plants and certain fungal groups like the Blastocladiomycota.
Q4. If two genetically different, haploid (n) hyphae underwent plasmogamy, what would be the genetic makeup of a resulting mycelium?
Correct Answer: (d)
Plasmogamy between two genetically distinct haploid hyphae produces a mycelium containing two or more genetically different types of nuclei. This state is known as being heterokaryotic.
Q5. If a fungus were found that lives in the skin of a mammal and protects the animal from harmful UV rays while absorbing small amounts of fatty acids from the animal’s skin that it uses as a nutrient, how would you characterize this interaction?
Correct Answer: (a)
In this scenario, both the mammal (protection from UV rays) and the fungus (obtaining nutrients) receive a benefit from the interaction. A biological interaction where both species benefit is defined as mutualism.
Q6. A fungal cell that contains two genetically identical nuclei is described as
Correct Answer: (b)
A homokaryon is a fungal cell or mycelium where all the nuclei are genetically identical. This is in contrast to a heterokaryon, which contains nuclei of different genetic origins.
Q7. In the context of fungal reproduction, what is the genetic makeup of a dikaryon?
Correct Answer: (c)
In many fungi, plasmogamy (fusion of cytoplasm) is not immediately followed by karyogamy (fusion of nuclei). The resulting stage, where a cell contains two separate haploid nuclei, is referred to as a dikaryon (n + n).
Q8. During what part of the life cycle of a typical basidiomycete would you expect to find a dikaryotic cell?
Correct Answer: (b)
In basidiomycetes, the primary mycelium consists of haploid (n) cells. Following plasmogamy, a secondary mycelium is formed, which is characteristically dikaryotic (n + n) and comprises the majority of the fungal body.
Q9. Which of the following is correct regarding the yeast Saccharomyces cerevisiae?
Correct Answer: (a) Saccharomyces cerevisiae is a unicellular ascomycete that reproduces primarily through an asexual process known as budding. It does not produce complex multicellular fruiting bodies like ascocarps.
Q10. Why would a drug targeting ribosomes be a poor choice for an antifungal to be used in humans, but a better choice for an antibiotic to be used in humans?
Correct Answer: (c)
Fungi and humans are both eukaryotes, meaning their ribosomes share a very similar structure and biochemical makeup. In contrast, bacteria are prokaryotes with distinct 70S ribosomes. A drug targeting fungal ribosomes would likely be toxic to human cells as well.
Q11. How is the relationship between a basidiomycete growing on a forest tree’s trunk and the forest tree best characterized?
Correct Answer: (d)
A fungus growing on a tree trunk is typically acting as a parasite, extracting nutrients from the living tree, or as a saprobe, decomposing dead wood. It is not forming a mutualistic mycorrhizal relationship, which occurs in the roots.
Q12. Fungal cell walls and some bacterial cell walls have which of the following in common?
Correct Answer: (b)
Fungal cell walls are composed of chitin, which is a polymer of N-acetylglucosamine. Bacterial cell walls contain peptidoglycan, which also features N-acetylglucosamine as one of its primary sugar components.
Q13. The rapid growth seen in fungi is largely due to which characteristic of unicellular and hyphal structures?
Correct Answer: (d)
The extensive branching of fungal hyphae creates a very high surface-area-to-volume ratio. This maximizes the area available for the absorption of nutrients and water from the environment, allowing for extremely rapid growth.
Continue in App
For the best quiz experience and detailed performance analytics, download the Master Biology App.