Module 4 (vocabulary is on Biology ipad app)

Question 0

Some biologists say that a mushroom is much like an iceberg, because only about 10% of an iceberg is visible from the surface of the ocean. What do the mean?

Answer 0

Typically, we see only the fruiting body of a mushroom. Like an iceberg, that visible part is only a small fraction of the total mushroom, because the mycelium is the largest component of a mushroom.

Question 1

Which of the following characteristics or structures exist for the vast majority of fungi? Which are present in only a few species?

Answer 1

Characteristics common to the majority of fungi were discussed in the section entitled “General Characteristics of Fungi.” It was noted, however, that of the specialized hyphae, only rhizoid hyphae are common to the vast majority of fungi.

Common to the majority of fungi:
extracellular to digestion
chitin
mycelia
hyphae
cells (all living creatures have them)
rhizoid hyphae

Present in only some:
stolons (specialized hyphae)
caps & stalks (only mushrooms have them)
sporangiophores (specialized hyphae with enclosed spores)
haustoria (specialized hyphae)
motile spores (Chytidiomycota & some slime molds)
septate hyphae (many on-septate hyphae)

Question 2

What is the difference between septate & nonseptate hyphae?

Answer 2

Septate hyphae have cell walls to separate the cells while non-septate hyphae do not.

Question 3

What is the function of the following specialized hyphae?

rhizoid hyphae, stolon, sporophore, haustorium

Answer 3

Rhizoid hyphae support the fungus and digest the food; a stolon asexually reproduces; a sporophore releases spores for reproduction; a haustorium invades the cells of a living host to absorb food directly from the cytoplasm.

Question 4

Which hyphae are aerial?

rhizoid hyphae, stolon, sporophore, haustorium

Answer 4

Stolons and sporophores

Question 5

What is the difference between sporangiophore and a conidiophore?

Answer 5

A sporangiophore produces its spores in an enclosure; a conidiophore does not.

Question 6

Give the main characteristics associated with each of the phyla of kingdom Fungi: Basidiomycota, Ascomycota, Zygomycota, Chytridiomycota, Deuteromycota, and Myxomycota.

Answer 6

Basidiomycota: Form sexual spores on club-like basidia
Ascomycota: Form sexual spores in sac-like asci
Zygomycota: Form sexual spores where hyphae fuse
Chytridiomycota: Form spores with flagella
Myxomycota: Fungi that look like protozoa for much of their lives

Question 7

Describe each of the stages (in chronological order) associated with the life cycle of a mushroom, starting with the formation of a mycelium.

Answer 7

A mushroom begins life as a small mycelium that grows from spores which have come from another mushroom. As the mycelium begins to grow, it might encounter a compatible mycelium. As the two mycelia begin to intertwine, their hyphae will sexually reproduce. Eventually, the newly-produced hyphae will form a complex web and enclose themselves in a membrane. When the hyphae are formed in the membrane, we say that the mushroom has reached the button stage of its existence. At that point, the hyphae begin filling with water quickly, and eventually the stipe and cap (the fruiting body) of the mushroom break through the membrane. The fruiting body of the mushroom releases its spores, which will grow into new mycelia if they land in suitable habitats.

Question 8

What is the main difference between shelf fungi, puffballs, and mushrooms?

Answer 8

Mushrooms form spores on basidia that exist in the gills of the cap, puffballs produce spores on the basidia enclosed in a membrane, and shelf fungi produce spores on basidia in pores on the fruiting body.

Question 9

What is an alternate host? List a type of fungus that uses one.

Answer 9

An alternate host is used by a parasitic fungus at some stage in its life. It is not the host that the fungus spends most of its life on; Rusts use alternate hosts

Question 10

What type of fungus is best known for fermentation? To which phylum does it belong?

Answer 10

Yeast are best known for fermentation. They belong to phylum Ascomycota.

Question 11

How is budding different from asexual reproduction in bacteria?

Answer 11

In budding, the offspring stays attached to the parent until it has grown. In bacterial asexual reproduction, the offspring grows on its own.

Question 12

Name at least two pathogenic fungi and the maladies that cause it.

Answer 12

1) rusts - crop damage
2) smuts - crop damage
3) ergot of rye (Claviceps purpurea) - death
4) Cryphonectria parasitica - chestnut blight
5) Ophiostoma ulmi - Dutch elm disease
6) Synchytrium endobioticum - potato wart

Question 13

Describe the three ways a bread mold can reproduce. In each case, specify whether the reproduction is sexual or asexual.

Answer 13

Bread mold can asexually reproduce when a stolon elongates and eventually starts another mycelium. It can also asexually reproduce when an aerial hypha forms a sporophore (typically a sporangiophore). Sexually, bread molds reproduce when two mycelia form a zygospore.

Question 14

What puts a fungus into phylum Deuteromycota?

Answer 14

If we do not know what its sexual mode of spore formation is, we place the fungus in phylum Deuteromycota.

Question 15

What can happen when an antibiotic is used too much?

Answer 15

If an antibiotic is used too much, resistant strains of the pathogen it is supposed to destroy can be formed.

Question 16

Name the genus of the fungus that produces penicillin.

Answer 16

Penicillin is extracted from a fungus in genus Penicillium.

Question 17

When a slime mold is a plasmodium, it resembles organisms from what kingdom?

Answer 17

In its feeding stage, a slime mold is a plasmodium. During that time, it resembles organisms from kingdom Protista.

Question 18

What is the easiest way to get rid of slime molds?

Answer 18

Keep the habitat dry, and all slime molds will die.

Question 19

What are two major forms of mutualism in which fungi participate? Describe each relationship and the job of each participant in that relationship.

Answer 19

Fungi participate in mutualism by forming lichens and mycorrhizae. A lichen is a mutualistic relationship between a fungus and an alga. The alga produces food for both creatures via photosynthesis, and the fungus supports and protects the alga. Mycorrhizae are mutualistic relationships between a fungus’ mycelium and a plant’s root system. The mycelium takes nutrients from the root while it collects minerals from the soil and gives them to the root.

Question 20

What is soredium?

Answer 20

A soredium is the specialized spore produced by most lichens. It contains spores for both the fungus and the alga.