Chapter 5 part II Fungi

Question 1

What are some examples of fungi used as food?

Answer 1

Mushrooms and truffles

Question 2

Fungi significance: Antibiotics

Answer 2

Examples: Penicillin, Cephalosporin, Cyclosporine, Mevinic acids.

Question 3

Mycology. How many species?

Answer 3

The study of fungi. Over 100,000 species, 200 pathogenic to humans.

Question 4

Mycoses

Answer 4

Diseases caused by fungi.

Question 5

Fungi nutrient acquisition facts

Answer 5

Nonphotosynthetic, chemoheterotrophs; absorb nutrients via secreted enzymes.

Question 6

What are saprobes?

Answer 6

Fungi that absorb nutrients from dead organisms.

Question 7

Fungal growth pH preference

Answer 7

Grow best at pH 5, which is too acidic for most bacteria.

Question 8

Molds vs. Yeasts

Answer 8

Molds: filamentous hyphae
Yeasts: unicellular, globular.

Question 9

Dimorphic fungi

Answer 9

Can switch between yeast and mold forms based on environmental conditions.

Question 10

Fungal cell walls

Answer 10

Composed of chitin and glucan; chitin is nitrogenous and flexible.

Question 11

Hyphae

Answer 11

Long filaments forming the body of molds; can be septate or coenocytic.

Question 12

Mycelium

Answer 12

Network of hyphae; aids in absorptive nutrition.

Question 13

Aerial hyphae

Answer 13

Hyphae that extend above the surface; produce spore structures.

Question 14

Mycorrhizae

Answer 14

Symbiotic associations with plant roots; help plants obtain phosphorus/nitrogen.

Question 15

Fungal asexual reproduction

Answer 15

Via hyphal growth, asexual production of spores (mitosis), or simple cell division: budding (yeasts).

Question 16

Fungal sexual reproduction; produce what?

Answer 16

Involves plasmogamy, karyogamy, meiosis; produces resistant spores.

Question 17

Mucoromycota

Answer 17

Phylum includes Rhizopus stolonifer (black bread mold); causes mucormycosis.

Question 18

Mucormycosis

Answer 18

Opportunistic infections in immunocompromised individuals (respiratory/sinus).

Question 19

Sporangium

Answer 19

Fungal cell that holds spores.

Question 20

Sporangiophore

Answer 20

Entire spore-bearing structure in Mucoromycota.

Question 21

Mucoromycete asexual reproduction

Answer 21

Via sporangiospores formed in sporangia.

Question 22

Mucoromycete sexual reproduction

Answer 22

Involves plasmogamy (zygosporangium), karyogamy, meiosis.

Question 23

Ascomycota

Answer 23

Diverse phylum: molds (Aspergillus), yeasts (Saccharomyces), mushrooms.

Question 24

Aspergillus

Answer 24

Pathogenic mold; produces aflatoxin (carcinogenic).

Question 25

Conidiophore

Answer 25

Hyphal structure producing asexual conidia (e.g., in Aspergillus).

Question 26

Conidia

Answer 26

Asexual spores formed on conidiophores.

Question 27

Ascus

Answer 27

Sac-like structure in Ascomycota containing ascospores (sexual spores) formed at the end of diploid growth. Where karyogamy occurs.

Question 28

Ascospore

Answer 28

Haploid spores produced via meiosis in asci.

Question 29

Saccharomyces cerevisiae

Answer 29

Baker’s yeast; used in bread/alcohol production; dimorphic.

Question 30

Candida albicans

Answer 30

Pathogenic yeast; causes vaginal/skin infections.

Question 31

Yeast budding

Answer 31

Asexual reproduction: daughter cell grows from mother cell.

Question 32

Pseudohyphae

Answer 32

Chains of elongated yeast cells resembling hyphae; 1 of 2 results of budding yeasts (other option is globular cell)

Question 33

Chitin

Answer 33

Strong, flexible nitrogenous polysaccharide in fungal cell walls; also in insect exoskeletons.

Question 34

Glucan

Answer 34

Polysaccharide containing sugars in fungal cell walls (not in mammalian cells); maintains osmotic stability.

Question 35

β-glucans

Answer 35

Type of glucan; important for fungal cell wall integrity.

Question 36

Fungal decomposers

Answer 36

Recycle organic waste via absorptive nutrition.

Question 37

Opportunistic fungi and ex.s

Answer 37

Cause disease in immunocompromised hosts (e.g., Aspergillus, Candida).

Question 38

Aflatoxin

Answer 38

Toxin by Aspergillus; damages DNA, causes liver cancer.

Question 39

Zygosporangium

Answer 39

Structure formed by fusion of mating types in Mucoromycota.

Question 40

Plasmogamy

Answer 40

Fusion of cytoplasm from two mating types; precedes karyogamy.

Question 41

Karyogamy

Answer 41

Fusion of nuclei to form a diploid zygote.

Question 42

Dikaryotic hyphae

Answer 42

Hyphae with two genetically distinct nuclei (in Ascomycota).

Question 43

Ascocarp

Answer 43

Fruiting body of Ascomycota where asci develop.

Question 44

Sterigmata

Answer 44

Cells radiating from vesicles; produce spores in Aspergillus & penicillium; can be uniseriate or biseriate sterigmata

Question 45

Uniseriate sterigmata

Answer 45

Single layer of spore-producing cells.

Question 46

Biseriate sterigmata

Answer 46

Two layers (metula → phialide → spores).

Question 47

Phialides

Answer 47

Cells that directly produce conidia in Aspergillus.

Question 48

Metula

Answer 48

Secondary spore-producing cells in biseriate sterigmata.

Question 49

Facultative anaerobes

Answer 49

Most yeasts; can grow with/without oxygen.

Question 50

Obligate aerobes

Answer 50

Most molds; require oxygen.

Question 51

Fungal spoilage: tolerate... Spoil...

Answer 51

Tolerate salt/acid/sugar; spoil jams, pickles, fruits.

Question 52

Mycotoxins and ex

Answer 52

Harmful fungal metabolites (e.g., aflatoxin).

Question 53

Immunosuppressant drugs

Answer 53

Cyclosporine: derived from fungi; prevents transplant rejection = makes transplants possible.

Question 54

Citric acid production

Answer 54

Fungi used industrially (e.g., soft drink industry).

Question 55

Black bread mold

Answer 55

Rhizopus stolonifer; common in environment, rots organic matter.

Question 56

Coenocytic hyphae

Answer 56

Hyphae without septa; multinucleated.

Question 57

Septate hyphae

Answer 57

Hyphae divided by cross-walls (septa).

Question 58

Fungal spores

Answer 58

Resistant to drying, heat, chemicals; aid dispersal.

Question 59

Germlings

Answer 59

Early hyphal growth from germinated spores.

Question 60

Vesicle (fungal)

Answer 60

Swollen structure supporting sterigmata in Aspergillus.

Question 61

What are some products that fungi are used in manufacturing?

Answer 61

Bread, alcoholic beverages, soy sauce, some cheeses, citric acid