Question 1

If all of their nuclei are equally active transcriptionally, then the cells of dikaryotic fungi, in terms of the gene products they can make, are essentially

Accepted Answer

Dikaryotic fungi have two genetically distinct nuclei per cell, similar to a diploid state, allowing them to produce gene products from both sets of chromosomes.

Question 2

Immediately after karyogamy occurs, which term applies?

Accepted Answer

Karyogamy is the process of fusion of two nuclei within a cell, leading to the formation of a single diploid nucleus. Therefore, immediately after karyogamy, the cell is considered diploid, containing two sets of chromosomes, one from each parent.

Question 3

Plasmogamy can directly result in which of the following? 1. cells with a single haploid nucleus
2) heterokaryotic cells
3) dikaryotic cells
4) cells with two diploid nuclei

Accepted Answer

Plasmogamy results in the fusion of two haploid cells with their nuclei remaining separate, leading to the formation of heterokaryotic cells which have two distinct haploid nuclei. These nuclei may or may not fuse later to form dikaryotic cells with two distinct haploid nuclei. Therefore, the correct choices are 2 or 3.

Question 4

Fossil fungi date back to the origin and early evolution of plants. What combination of environmental and morphological change is similar in the evolution of both fungi and plants?

Accepted Answer

Both fungi and plants evolved to colonize land, which required adaptations such as loss of flagellated cells and the ability to withstand desiccation.

Question 5

Which of the following characteristics is unique to chytrids compared to other groups of fungi?

Accepted Answer

Chytrids are unique among fungi because they have flagellated spores, known as zoospores, which is a characteristic not found in other fungal groups.

Question 6

Which of the following is a characteristic of hyphate fungi (fungi featuring hyphae)?

Accepted Answer

Hyphate fungi feature long, branching filaments called hyphae, which give them an advantage in rapid directional growth towards food sources. A is incorrect because hyphate fungi acquire nutrients through absorption, not phagocytosis. B is incorrect because hyphate fungi have a multicellular body plan. C is incorrect because cellulose microfibrils are found in the cell walls of plants, not fungi. E is incorrect because while some hyphate fungi can reproduce asexually through budding, not all do so.

Question 7

Which process occurs in fungi and has the opposite effect on a cell's chromosome number than does meiosis I?

Accepted Answer

Karyogamy is the process in fungi where two haploid nuclei fuse to form a diploid nucleus, resulting in an increase in the chromosome number of the cell. This is the opposite effect of meiosis I, which reduces the chromosome number. Option A, mitosis, also results in an increase in the number of chromosomes, but it is not opposite of meiosis I in terms of chromosome number. Options B, C, and D, are not related to chromosome number changes.

Question 8

Which of the following has the least affiliation with all of the others?

Accepted Answer

Lichens represent a symbiotic relationship between a fungus and a photosynthetic partner (usually an alga or cyanobacterium), which is distinct from the other options that are more directly related to the mutualistic relationships between fungi and plant roots (mycorrhizae, specifically arbuscular mycorrhizae involving Glomeromycota and arbuscules).

Question 9

The vegetative (nutritionally active) bodies of most fungi are

Accepted Answer

The vegetative bodies of most fungi are composed of hyphae, they are referred to as mycelium and are usually underground. All of these responses are correct.

Question 10

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?

Accepted Answer

Prokaryotes, such as bacteria, are the most likely group of organisms to benefit from the sudden removal of fungal decomposers. This is because prokaryotes and fungi often compete for the same resources, such as dead organic matter. With the absence of fungal competitors, prokaryotes would be able to consume and break down more organic material, leading to an increase in their population size.

Question 11

If intelligent extraterrestrials visited Earth 475 million years ago, and then again 300 million years ago (at the close of the Carboniferous period), what trends would they have noticed in Earth's terrestrial vegetation over this period? 1. a trend from dominant gametophytes to dominant sporophytes
2) a trend from sporangia borne on modified leaves (sporophylls) to sporangia borne on stalks (seta)
3) a trend from no true leaves, to microphylls, to megaphylls
4) a trend from soil-surface-hugging plants to "overtopping" plants
5) a trend toward increased lignification of conducting systems

Accepted Answer

Option 1 is correct as there was a shift from dominant gametophytes (in which the haploid generation is more predominant) to dominant sporophytes (in which the diploid generation is more predominant) during the course of evolution.
Option 3 is correct as over the course of evolution, plants evolved from not having true leaves to developing microphylls (single veined leaves) and then to megaphylls (leaves with a highly branched vascular system).
Option 4 is correct as there was a trend toward overtopping plants i.e., plants that grew taller and higher than the surrounding vegetation to capture maximum sunlight for photosynthesis.
Option 5 is correct as there was an increase in lignification (the process of making the cell walls rigid and woody) of conducting systems during the course of evolution, which helped plants to transport water and nutrients more efficiently and to withstand the gravitational forces associated with overtopping growth.

Question 12

The hydrolytic digestion of which of the following should produce monomers that are aminated (i.e., have an amine group attached) molecules of β-glucose?

Accepted Answer

The answer of The hydrolytic digestion of which of the...

Question 13

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

Accepted Answer

In most fungi, karyogamy (fusion of nuclei) does not immediately follow plasmogamy (fusion of cytoplasm), resulting in heterokaryotic or dikaryotic cells with multiple haploid nuclei. This condition allows fungi to experience extended periods of haploid growth and, in some species, allows for sexual reproduction in specialized structures.

Question 14

In seed plants, which of the following is part of a pollen grain and has a function most like that of the seed coat?

Accepted Answer

Sporopollenin is a tough polymer that forms the outer layer of a pollen grain. It is similar in function to the seed coat of a seed, as it helps protect the male gametophyte during dispersal and prevents dehydration.

Question 15

Which of these paired fungal structures are structurally and functionally most alike?

Accepted Answer

Haustoria and arbuscules are both specialized fungal structures that allow for nutrient exchange with plant hosts. Haustoria are modified hyphae that penetrate the plant cell walls and facilitate nutrient uptake, while arbuscules are tree-like structures formed within plant cells that allow for nutrient exchange between the plant and fungal cells. The other options are not structurally or functionally similar.

Question 16

When pathogenic fungi are found growing on the roots of grape vines, grape farmers sometimes respond by covering the ground around their vines with plastic sheeting and pumping a gaseous fungicide into the soil. The most important concern of grape farmers who engage in this practice should be that the

Accepted Answer

Mycorrhizae are beneficial fungi that live in association with plant roots, helping them to absorb nutrients from the soil. If the fungicide used to treat the pathogenic fungi also kills mycorrhizae, it could have a detrimental effect on the health of the grape vines. Therefore, grape farmers should be most concerned about the impact of the fungicide on mycorrhizae.

Question 17

Which description does not apply equally well to both sexual and asexual spores?

Accepted Answer

Asexual spores are not produced by meiosis, but rather by mitosis, whereas sexual spores are produced by meiosis.

Question 18

A botanist discovers a new species of land plant with a dominant sporophyte, chlorophylls a and b, and cell walls made of cellulose. In assigning this plant to a phylum, which of the following, if present, would be least useful?

Accepted Answer

The answer of A botanist discovers a new species of...

Question 19

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

Accepted Answer

Fungal mycelium secretes enzymes to break down complex organic matter into smaller molecules that can be absorbed as nutrients.

Question 20

Which of the following terms refers to symbiotic relationships that involve fungi living between the cells in plant leaves?

Accepted Answer

Endophytes are organisms, often fungi, that live within plant tissues without causing harm to the host plant. In the case of fungi living between the cells in plant leaves, they are considered endophytes. Mycorrhizae refers to a symbiotic relationship between fungi and plant roots, while lichens are symbiotic relationships between fungi and photosynthetic organisms (such as algae). Pathogens are organisms that cause disease. Endosymbioses refer to symbiotic relationships in which one organism lives within another organism's cells.

Quiz 26: The Colonization of Land by Plants and Fungi