Question 1

How many species of fungi are there?

Accepted Answer

The kingdom Fungi includes an enormous variety of living organisms collectively referred to as Eumycota , or true Fungi. While scientists have identified about 100,000 species of fungi, this is only a fraction of the 1.5 million species of fungus likely present on Earth.

Question 2

What are some examples of fungi?

Accepted Answer

Edible mushrooms, yeasts, black mold, and the producer of the antibiotic penicillin, Penicillium notatum , are all members of the kingdom Fungi.

Question 3

Are fungi autotrophic or heterotrophic?

Accepted Answer

Fungi are not capable of photosynthesis; they are heterotrophic because they use complex organic compounds as sources of energy and carbon.

Question 4

What are the fungi reproduction strategies?

Accepted Answer

Some fungal organisms multiply only asexually, whereas others undergo both asexual reproduction and sexual reproduction with alternation of generations. Most fungi produce a large number of spores, which are haploid cells that can undergo mitosis to form multicellular, haploid individuals.

Question 5

What are mycorrhizae?

Accepted Answer

A mutualistic relationship between a plant and a fungus. Mycorrhizae are connections between fungal hyphae, which provide soil minerals to the plant, and plant roots, which provide carbohydrates to the fungus.

Question 6

What is Dutch elm disease?

Accepted Answer

A serious infection caused by the fungus Ophiostoma ulmi . It is a particularly devastating type of fungal infestation that destroys many native species of elm ( Ulmus sp.). The fungus infects the vascular system of the tree, which blocks water flow within the plant and mimics drought stress. The elm bark beetle acts as a vector, transmitting the disease from tree to tree. Accidentally introduced in the early 1930s, the fungus decimated elm trees across the continent. Many European and Asiatic elms are less susceptible to Dutch elm disease than American elms.

Question 7

What is the impact of fungal infections on humans?

Accepted Answer

In humans, fungal infections are generally considered challenging to treat. Unlike bacteria, fungi do not respond to traditional antibiotic therapy, since they are eukaryotes. Fungal infections may prove deadly for individuals with compromised immune systems.

Question 8

What are some of the commercial applications of fungi?

Accepted Answer

The food industry uses yeasts in baking, brewing, and cheese and wine making. Many industrial compounds are byproducts of fungal fermentation. Fungi are the source of many commercial enzymes and antibiotics.

Question 9

What is a spore?

Accepted Answer

A haploid cell that can undergo mitosis to form a multicellular, haploid individual.

Question 10

What is a coenocytic hypha?

Accepted Answer

Single hypha that lacks septa and contains many nuclei.

Question 11

What are facultative anaerobes?

Accepted Answer

Organisms that can perform both aerobic and anaerobic respiration and can survive in oxygen-rich and oxygen-poor environments.

Question 12

What is a haustoria?

Accepted Answer

Modified hypha on many parasitic fungi that penetrate the tissues of their hosts, release digestive enzymes, and/or absorb nutrients from the host.

Question 13

What does it mean to be heterothallic?

Accepted Answer

Describes when only one mating type is present in an individual mycelium.

Question 14

What does it mean to be homothallic?

Accepted Answer

Describes when both mating types are present in mycelium.

Question 15

What is a hypha?

Accepted Answer

Fungal filament composed of one or more cells. Plural: hyphae.

Question 16

What is karyogamy?

Accepted Answer

Fusion of nuclei.

Question 17

What is a mycelium?

Accepted Answer

Mass of fungal hyphae.

Question 18

What is mycology?

Accepted Answer

Scientific study of fungi.

Question 19

What are obligate aerobes?

Accepted Answer

Organisms, such as humans, that must perform aerobic respiration to survive.

Question 20

What are obligate anaerobes?

Accepted Answer

Organisms that only perform anaerobic respiration and often cannot survive in the presence of oxygen.

Question 21

What is plasmogamy?

Accepted Answer

Fusion of cytoplasm.

Question 22

What is a saprobe?

Accepted Answer

Organism that derives nutrients from decaying organic matter; also saprophyte.

Question 23

What is a septum?

Accepted Answer

Cell wall division between hyphae. Plural: septa

Question 24

What is a sporangium?

Accepted Answer

Reproductive sac that contains spores.

Question 25

What is a thallus?

Accepted Answer

Vegetative body of a fungus. May be unicellular or multicellular.

Question 26

What is a yeast?

Accepted Answer

General term used to describe unicellular fungi.

Question 27

What are some reasons why fungi were previously classified as plants?

Accepted Answer

Fungi arose mostly sessile and seemingly rooted in place. They possess a stem-like structure similar to plants, as well as having a root-like fungal mycelium in the soil.

Question 28

When did fungi first evolve?

Accepted Answer

Based on fossil evidence, fungi appeared in the pre-Cambrian era, about 950 million years ago.

Question 29

Where are fungi found in the phylogenetic tree?

Accepted Answer

Molecular biology analysts of the fungal genome demonstrates that fungi are more closely related to animals than plants. They are a polyphyletic group of organisms that share characteristics, rather than sharing a common ancestor.

Question 30

Which degrees are usually required to become a mycologist?

Accepted Answer

Mycology is a branch of microbiology, and many mycologists start their careers with a degree in microbiology. To become a mycologist, a bachelor's degree in a biological science (preferably majoring in microbiology) and a master's degree in mycology are minimally necessary.

Question 31

What are some fields that mycologists can specialize in?

Accepted Answer

Taxonomy and fungal genomics, molecular and cellular biology, plant pathology, biotechnology, or biochemistry.

Question 32

In what ways may mycologists practice medicine?

Accepted Answer

Some medical microbiologists concentrate on the study of infectious diseases caused by fungi (mycoses).

Question 33

What are some examples of fungal infections identified and controlled by mycologists in collaboration with cross-disciplinary scientists?

Accepted Answer

Mycologists collaborate with zoologists and plant pathologists to identify and control difficult fungal infections, such as the devastating chestnut blight, the mysterious decline in frog populations in many areas of the world, or the deadly epidemic called white nose syndrome, which is decimating bats in the eastern United States.

Question 34

What are some ways in which mycologists are employed in the public sector?

Accepted Answer

Government agencies hire mycologists as research scientists and technicians to monitor the health of crops, national parks, and national forests.

Question 35

What are some ways in which mycologists are employed in the private sector?

Accepted Answer

Mycologists are employed in the private sector by companies that develop chemical and biological control products or new agricultural products, and by companies that provide disease control services.

Question 36

Why are mycologists employed in the food industry?

Accepted Answer

Because of the key role played by fungi in the fermentation of alcohol and the preparation of many important foods, scientists with a good understanding of fungal physiology routinely work in the food technology industry.

Question 37

How is mycology used in wine-making?

Accepted Answer

Oenology, the science of wine making, relies not only on the knowledge of grape varietals and soil composition, but also on a solid understanding of the characteristics of the wild yeasts that thrive in different wine-making regions. It is possible to purchase yeast strains isolated from specific grape-growing regions.

Question 38

Who discovered the process of fermentation?

Accepted Answer

The great French chemist and microbiologist, Louis Pasteur, made many of his essential discoveries working on the humble brewer's yeast, thus discovering the process of fermentation.

Question 39

Does horizontal gene transfer occur in fungi?

Accepted Answer

A few types of fungi have structures comparable to bacterial plasmids, however the horizontal transfer of genetic information from one mature fungus to another rarely occurs in fungi.

Question 40

In what ways do fungal cells differ from plant cells?

Accepted Answer

Unlike plant cells, fungal cells do not have chloroplasts or chlorophyll.

Question 41

What are some properties of fungal pigments?

Accepted Answer

Many fungi display bright colors arising from other cellular pigments, ranging from red to green to black. Pigments in fungi are associated with the cell wall and play a protective role against ultraviolet radiation. Some fungal pigments are toxic.

Question 42

What is Amanita muscaria (fly agaric)?

Accepted Answer

A poisonous mushroom native to temperate and boreal regions of North America that is recognizable by its bright red cap and white patches.

Question 43

What are some properties of fungal cell walls?

Accepted Answer

Like plant cells, fungal cells have a thick cell wall. The rigid layers of fungal cell walls contain complex polysaccharides called chitin and glucans. Chitin, also found in the exoskeleton of insects, gives structural strength to the cell walls of fungi. The wall protects the cell from desiccation and predators.

Question 44

How do the plasma membranes of fungal cells differ from those of animal cells?

Accepted Answer

Fungi have plasma membranes similar to other eukaryotes, except that the structure is stabilized by ergosterol: a steroid molecule that replaces the cholesterol found in animal cell membranes.

Question 45

What is the motility of fungi?

Accepted Answer

Most members of the kingdom Fungi are nonmotile. Flagella are produced only by the gametes in the primitive phylum Chytridiomycota.

Question 46

What are dimorphic fungi?

Accepted Answer

Dimorphic fungi can change from the unicellular to multicellular state depending on environmental conditions.

Question 47

What are some examples of unicellular fungi?

Accepted Answer

Saccharomyces cerevisiae (baker's yeast) and the Candida species, including Candida albicans (the agent of candidiasis and thrush, a common fungal infection)

Question 48

What are the morphological stages of multicellular fungi?

Accepted Answer

Most fungi are multicellular organisms. They display two distinct morphological stages: the vegetative and reproductive. The vegetative stage consists of a tangle of slender thread-like structures called hyphae, whereas the reproductive stage can be more conspicuous.

Question 49

How large are hyphae?

Accepted Answer

Although individual hyphae must be observed under a microscope, the mycelium of a fungus can be very large.

Question 50

What is Armillaria ostoyae/Armillaria solidipes (honey mushroom)?

Accepted Answer

A giant fungus that is considered to be the largest organism on Earth, spreading across more than 2000 acres of underground soil in eastern Oregon. It is estimated to be at least 2400 years old.

Question 51

What is the effect of Neotestudina rosati on humans?

Accepted Answer

The mycelium of the fungus Neotestudina rosati can be pathogenic to humans. The fungus enters through a cut or scrape and develops a mycetoma, a chronic subcutaneous infection.

Question 52

Are fungal hyphae separated by septa?

Accepted Answer

Most fungal hyphae are divided into separate cells by endwalls called septa (septated). In most phyla of fungi, tiny holes in the septa allow for the rapid flow of nutrients and small molecules from cell to cell along the hypha. They are described as perforated septa. The hyphae in bread molds (which belong to the phylum Zygomycota ) are not separated by septa. Instead, they are formed by large cells containing many nuclei, an arrangment described as coenocytic hyphae.

Question 53

In which environmental conditions can fungi be found?

Accepted Answer

Fungi thrive in environments that are moist and slightly acidic, and can grow with or without light. They vary in their oxygen requirement. Most fungi are obligate aerobes, other species are obligate anaerobes, and some are intermediate, being facultative anaerobes.

Question 54

What is an example of fungi that are obligate anaerobes?

Accepted Answer

The chytridiomycetes that reside in the rumen of cattle are obligate anaerobes.

Question 55

Do yeasts require oxygen?

Accepted Answer

Yeasts are facultative anaerobes. The alcohol produced from yeast fermentation is used in wine and beer production.

Question 56

In what ways is fungal nutrition similar to animal nutrition?

Accepted Answer

Like animals, fungi are heterotrophs; they use complex organic compounds as a source of carbon, rather than fix carbon dioxide from the atmosphere as do some bacteria and most plants. In addition, fungi do not fix nitrogen from the atmosphere. Like animals, they must obtain it from their diet. As with animal cells, the polysaccharide of storage is glycogen, rather than starch, as found in plants.

Question 57

In what ways is fungal nutrition different from that of animals?

Accepted Answer

Unlike most animals, which ingest food and then digest it internally in specialized organs, fungi perform these steps in the reverse order; digestion precedes ingestion. First, exoenzymes are transported out of the hyphae, where they process nutrients in the environment. Then, the smaller molecules produced by this external digestion are absorbed through the large surface area of the mycelium.

Question 58

What role do fungi play in an ecosystem?

Accepted Answer

Fungi are mostly saprobes; they obtain their nutrients from dead or decomposing organic matter: mainly plant material. Fungal exoenzymes are able to break down insoluble polysaccharides, such as the cellulose and lignin of dead wood, into readily absorbable glucose molecules. The carbon, nitrogen, and other elements are thus released into the environment.

Question 59

How can fungi be used in bioremediation?

Accepted Answer

Because of their varied metabolic pathways, fungi fulfill an important ecological role and are being investigated as potential tools in bioremediation. For example, some species of fungi can be used to break down diesel oil and polycyclic aromatic hydrocarbons (PAHs). Other species take up heavy metals, such as cadmium and lead.

Question 60

What are some examples of parasitic fungi in plants?

Accepted Answer

Smut and Dutch elm disease.

Question 61

What are some examples of parasitic fungi in humans?

Accepted Answer

Athlete's foot and candidiasis (thrush).

Question 62

What are some nutrition strategies for fungi in nitrogen-poor environments?

Accepted Answer

In environments poor in nitrogen, some fungi resort to predation of nematodes (small non-segmented roundworms). Species of Arthrobotrys fungi have a number of mechanisms to trap nematodes. One mechanism involves constricting rings within the network of hyphae. The rings swell when they touch the nematode, gripping it in a tight hold. The fungus penetrates the tissue of the worm by extending specialized hyphae called haustoria.

Question 63

What are perfect vs. imperfect fungi?

Accepted Answer

Perfect fungi reproduce both sexually and asexually, while the so-called imperfect fungi reproduce only asexually (by mitosis).

Question 64

In which type of reproduction are fungal spores produced?

Accepted Answer

In both sexual and asexual reproduction.

24: Fungi Flashcards

Characteristics of Fungi, Classifications of Fungi, Ecology of Fungi, Fungal Parasites and Pathogens, Importance of Fungi in Human Life

Brainscape's Knowledge GenomeTM

24: Fungi Flashcards

Characteristics of Fungi, Classifications of Fungi, Ecology of Fungi, Fungal Parasites and Pathogens, Importance of Fungi in Human Life

Brainscape's Knowledge Genome^TM