Introduction to Fungi
1. Define:
Mycology - Mycology is the science or study of fungi or Myceteae.
Hyphae - Hyphae are microscopic, thread-like filaments that form the body or thallus of a mold-type fungus. Multiple hyphae typically come together to form a mat visible to the naked eye.
Karyogamy - Karyogamy is the second stage in the sexual reproductive processes of fungi. (Karyon=nucleus, gamous=union or marriage) During karyogamy, two haploid nuclei join or fuse to form a diploid zygote.
Dermatophytes - The term dermatophyte applies to a group of fungi that cause superficial mycoses. Three important genera within this group are Microsporum, Trichophyton, and Epidermophyton.
Opportunistic pathogen - Microorganisms are considered opportunistic pathogens if they are usually free-living (often in soil, or in or on the body) but will take advantage of a weakened host, e.g., one that is suffering from preexisting disease, or has a compromised immune system. Fungi such as Candida albicans and Cryptococcus neoformans are frequently opportunistic pathogens.
2. mycology
3. achlorophyllous/ chemoheterotrophic
4. eukaryotic
5. hyphae/ haustoria
6. mycelium/ syncytium
7. mycorrhizae
8. aerial mycelium/ vegetative mycelium
9. budding or the formation of blastospores
10. sporangeospores
11. plasmogamy/ meiosis
12. karyogamy/ meiosis
13. Fungi are beneficial in a number of ways, they are saprotrophs/saprophytes that break down or decompose dead organic material, they form mycorrhizae that are beneficial to forest trees, they may be used as a food source, they are used in food processing/preparation (bread, cheese, wine, etc.), they are a source of antibiotics, they are used as research tools, and are used industrially to produce enzymes, organic acids and solvents. Yeast cells can also be genetically modified to produce human proteins.
14. organic acids and solvents/ enzymes
15. mycoses/ antibiotics
16. mycoses/ systemic/ respiratory tract
17. There are three factors known to have caused increases in mycoses, including: 1) an increase in the widespread use of antimicrobial drugs (these tend to kill normal bacterial flora that help to keep fungus populations in check), 2) increased use of chemotherapeutic agents that damage the immune system (cancer chemotherapy and immunosuppression in association with organ transplants), and 3) increases in HIV infection and the incidence of AIDS (acquired immune deficiency syndrome).
18. the condition of their immune system, i.e., if or not their immune system is functioning properly. People with compromised immune systems are much more susceptible to fungal infection than are normal, healthy individuals.
19. Coccidioides, Histoplasma, Cryptococcus, Aspergillus, Rhizopus and Candida are common opportunistic pathogens; however, multiple other types of fungi can cause systemic mycoses in immunocompromised individuals.
20. dermatophytes/ tinea pedis (athletes foot) - tinea corporis/tinea capitis (ringworm of body/head or scalp)
21. Histoplasma, Coccidioides, Aspergillus, or Rhizopus/ respiratory tract
22. aflatoxin
23. Amanita and Aspergillus
24. Rhizopus
25. H,F,G,A,C,B,D,E
Copyright 2002 Sierra College Biological Sciences Department
Last updated: 01/18/02.
