Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology Lab Exam 2 > Fungi > Flashcards

Fungi Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

How is alternation of generations different in fungi?

A

Fungi don’t have distinct male/female individuals or gametes. They also don’t have distinct, separate gametes. Instead, individuals in a fungal species are of different genetic mating types. Different mating types thus recognize each other and mate, ensuring cross-fertilization.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Fungi are essentially what?

A

Filamentous strands of cells that secrete enzymes and feed on the organic material on which they are growing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the hypha

A

A slender filament of cytoplasm and nuclei enclosed by a cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a mass of hyphae?

A

Mycelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why are fungi known as absorptive heterotrophs?

A

The hyphae of the fungus secretes enzymes for extracellular digestion of the organic substrate. Then the mycellium and hyphae absorb the digested nutrients.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Fungi feed on different substrates. What are the two types of fungi and their substrate sources?

A

Fungi that get food from seat organic matter- saprophytes
Fungi that feed on living organisms- parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is modified in a parasitic fungi?

A

They have modified hyphae called haustoria (thin extensions of the hyphae that penetrate living cells to absorb nutrients)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does Hyphae differentiate in fungi species?

A

Some species of fungi have hyphae with crosswalls called (septa ) the role of the (septa ) is to separate cytoplasm and nuclei into cells.
Other species have incomplete/ no (septa ) and are therefore coenocytic (multinucleate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the cell walls of fungi made of?

A

Chitin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Asexual reproduction in fungi:

A

Budding, Fragmentation, or mitotic production of haploid cells called spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What species of fungi used mitotic spore production and points its sporangia towards the sun? (phototaxis)

A

Pilobolus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does budding occur? Provide an example.

A

Budding is mitosis followed by an uneven distribution of cytoplasm. After budding, an outgrowth of the original cell detaches and matures into a new organism. Ex) yeasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the process of Fragmentation?

A

The breaking of an organism into one or more pieces, each of which can develop into a new individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Events that occur during sexual reproduction of fungus:

A

Vegetative growth, genetic recombination, meiosis, and nuclear fusion ( karyogamy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When does sexual reproduction occur in fungi?

A

When hyphae of 2 genetically different individuals of the same species encounter each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe process of plasmogamy

A

Haploid cells from 2 mating strains fuse their cytoplasm and become dikaryotic (n+n) with 2 nuclei per cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens after Plasmogamy?

A

Karyogamy- nuclei fuse to become diploid (2n) zygotes. (the process is equivalent to fertilization)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Nuclei of a fungal mycellium are

A

Haploid during most of the life cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Gametes are produced by _
and haploid cells are produced by _

A

Mitosis and Meiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

In the life cycle of a fungus, sexual reproduction produces 2 haploid gametes to form a diploid zygote. Whereas, in the asexual life cycle, mitosis produces haploid spores.
After the zygote forms in sexual reproduction, meiosis occurs and forms haploid spores and the cycle continues.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How are fungi typically classified

A

By modifications of hyphae into varied and specialized reproductive structure unique to a phylum, genus, or species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the 4 major groups of fungi phyla?

A

Chytridiomycota, Zygomycota, Ascomycota, and Basidiomycota

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is considered the most ancient fungi?

A

Chytrids

24
Q

Characteristics of chytrids:

A

They are typically aquatic saprobes or parasites on plants, animals, and protists. Their distinctive feature is motile spores with flagella.

25
Q

The impact of chytrids:

A

Infections have significantly reduced the populations of many amphibians

26
Q

Characteristics of Zygomycota

A

There are 750 species of Zygomycetes, which include common bread molds. They get their name from resting sexual structures called zygosporangia. Zygomycetes are saprophytic and their vegetative hyphae lack (septa )- they are aseptate

27
Q

What is a common genus of bread mold?

A

Rhizopus

28
Q

What is Rhizopus also known as?

A

Black bread mold

29
Q

Describe the structure of Rhizopus:

A

It’s hyphae are modified into rhizoids (hold fasts), stolons (connecting hyphae), and sporangiospores (supportive stem-like filaments), and sporangia (sites of asexual haploid spore formation)

30
Q

Rhizopus is Isogamus. What does this mean?

A

(Gametes from both strains look alike) The strains are not called male and female but are rather, + or - (The 2 strains free toward each other and formed reproductive structures called gametangia)

31
Q

Sexual Reproduction in Rhizopus:

A

1- +and- hyphae make contact
2- gametangia form and appear as swellings
3-The wall between the gametangia breaks down, and cells fuse (plasmogamy). Fusion of nuclei (karyogamy) follows and occurs in the zygosporangium
4- Note: except for the zygotes, all other nuclei are haploid
5- The zygotes then undergo meiosis (one or more resulting haploid spores soon germinate)
6- The hyphae of the germinating cells break out of the zygosporangium and produce sporophyte via mitosis to form spores asexually.

32
Q

Describe Phylum Ascomycota (sac fungi):

A

Includes 30,000 species such as yeasts, some molds, morels, and truffles. It’s name is derived from a microscopic, sac shaped, sexual reproductive structure called an ascus. (Sexual spores borne internally in sacs called asci)

33
Q

How do ascomycetes reproduce asexually?

A

By forming spores called conidia- (Modified hyphae called conidiophores partition nuclei in longitudinal chains of beadlike conidia.) Each conidium contains one or more nuclei Conidia form on the surface of conidiophores and when mature, conidia are released in large numbers to germinate and produce new organisms.

34
Q

What are examples of fungi that form conidia?

A

Aspergillus and Penicillum

35
Q

What are fungal species that produce only asexual conidia called traditionally?

A

Fungi imperfecti or deuteromycota

36
Q

What are most fungi with no sexual phase most likely known as?

A

Ascomycetes that have lost their ability to sexually reproduce

37
Q

How are ascomycetes economically
important? Provide examples:

A

1-Penicillum produce antibiotics.
2-Penicillium roquefortii- gives flavor to Roquefort cheese. [found in caves in France ]
3-Aspergillus oryzae- used to brew Japanese saki and enrich food for livestock.

38
Q

Do yeast cells for conidia?

A

No. While they are common unicellular ascomycetes, most of their reproduction is by budding or cell fission. As for occasional sexual reproduction, 2 sexually reproducing yeast cells will fuse to form one cell with 2 nuclei. This cell functions as an ascus in which syngamy is followed immediately by meiosis.

39
Q

The yeast used to produce wine and beer is called what?

A

Saccharomyces cerevisiae

40
Q

Sexual Reproduction in Ascomycota:
How does it begin and what forms from the contact of monokaryotic hyphae?

A

It begins with the contact of the hyphae from 2 mating strains. Where the hyphae touch, large multinucleate swellings appear. (Antheridia and ascogonia) which eventually fuse. Haploid nuclei of the 2 strains intermingle in the swelling (ascogonium)

41
Q

Sexual reproduction in Ascomycota:
What grows from the swelling?

A

A dikaryotic mycelium.
(Each dikaryotic cell has one nucleus from each parent; the nuclei do not fuse immediately)

42
Q

Sexual Reproduction in Ascomycota:
What occurs after the dikaryotic mycelium grow from the swelling?

A

Dikaryotic hyphae grow and mingle with monokaryotic hyphae from each parent to form a cup-shaped ascocarp.

43
Q

Sexual Reproduction in Ascomycota:
What has to occur for the nucleus to fuse (karyogamy)

A

Dikaryotic cells lining the inside of the ascocarp form sac shaped asci. (Ascus)
The nuclei can then fuse in each ascus to form a zygote.

44
Q

Sexual Reproduction in Ascomycota:
What occurs after karyogamy?

A

After fusion, meiosis produces 4 haploid ascospores.
Subsequent mitosis produces 8 ascospores within each mature ascus.

45
Q

Sexual Reproduction in Ascomycota:
How are the ascospores released?

A

The asci on the surface of the ascocarp rupture and release ascospores into the environment.
Each ascospore can then produce a new mycelium

46
Q

Phylum Basidiomycota (club fungi) characteristics:

A

Basidiomycetes (25,000 species) are the most familiar of fungi. They include mushrooms, puffballs, shelf fungi, and economically important plant pathogens such as rusts and smuts. (Basidiomycota derives it’s name from the characteristic sexual reproductive structure, the basidium)- sexual spores are borne externally on club- shaped structures called basidia. Some club fungi can also reproduce asexually by conidia formation

47
Q

Types of Basidiomycota:

A

Agaricus campestris is a common field mushroom, and it’s close relative A. Bisporus is cultivated for more than 60,000 tons of food per year in the United States.
The Amanita phaloides “the destroying angel mushroom” is fatal when consumed

48
Q

Sexual Reproduction in Basidiomycota:
How does plasmogamy occur?

A

Haploid hyphae from different mating strains permeate the substrate. Septa then form between the nuclei in the hyphae to form monokaryotic primary mycelia. (A monokaryotic mycelium has one nucleus in each cell) Cells of the primary mycelia of different mating strains fuse (plasmogamy) and produce dikaryotic secondary mycelium.

49
Q

Sexual Reproduction in Basidiomycota:
How is the basidiocarp formed?

A

First, the secondary mycelium grows in the substrate. The dikaryotic hyphae of the secondary mycelium eventually coalesce and protrude above the substrate as a tight bundle of hyphae called basidiocarp (which then forms a cap and gills)

50
Q

Sexual Reproduction in Basidiomycota:
What are the sites of sexual reproduction?

A

Dikaryotic, club shaped basidia form on the surface of the gills. Basidia are the sites of sexual reproduction. (Especially meiosis)

51
Q

Sexual Reproduction in Basidiomycota:
What happens after the basidia are formed?

A

The 2 nuclei in each basidium fuse (karyogamy) to form a diploid zygote.
Next, the zygote undergoes meiosis to produce haploid basidiospores.
The basidiospores are then released from basidia lining the gills and are dispersed by wind ( A basidiospore germinates into a new mycellium)

52
Q

What are Lichens?

A

They are brightly colored organisms found on most hard substrates. A lichen includes an ascomycete (rarely other fungi) living symbiotically with a photosynthetic alga (a protist) or Cyanobacterium.

53
Q

Define Symbiosis:

A

Living in close and sometimes dependent association

54
Q

Which genera of algae occur in different species of lichen.

A

About 26 genera of algae occur in different species of lichen. However, the green algae Trebouxia and Trentepohlia and the cyanobacterium Nostoc are in 90 percent of lichen species.

55
Q

How do lichens reproduce?

A

They reproduce asexually by releasing fragments of tissue or specialized, stress resistant packets of fungal and algal cells. Each of the 2 components (fungus and alga) May reproduce sexually by mechanisms characteristic of their phylum, and the new organisms may continue the lichen association.

56
Q

What are the 3 basic growth forms of lichens?

A

Crustose, Foliose, and Fruticose
The thallus of Crustose lichens grow closer to the surface of a hard substrate such as a rock or bark. The lichen is flat and 2D. Foliose lichens adhere to their substrate, but some of the thallus peels and folds away from the substrate in small sheets. Fruticose lichens are 3D and often grow away from the substrate with erect stalks. The tips of the stalks are often sites of ascus formation by sexually reproducing ascomycete symbiont

57
Q

Lichens are extremely sensitive to air pollution. True or False

A

True (they are adapted to efficiently absorb nutrients and minerals from the air)

Biology Lab Exam 2 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions