Saturday 1 November 2014

11th Lecture: 31/10/14

Topic: Algae and Fungi

Notes:
1) Fungi are spore-bearing organisms which exist as a single kingdom.
2) Most Fungi are multicellular except for yeast which are unicellular.
3) Cell wall of fungi is made up of chitin and they store glycogen. They can reproduce sexually and asexually.
4) Fungi can found in primary terrestial and aquatic environment.
5) The body structure of a fungus is called thallus. Thallus consists of long,branched hyphae filaments, tangled into a mycelium mass.
6) The feeding forms of fungi : Mutualistic, Parasitic, saprobic.
7) Telomorphic Fungi produce sexual and asexual spores only. Anamorphic spores procude asexual spores only.
8) Fungus can undergo mitosis to produce a daughter cell through asexual reproduction (budding).
9) Sexual reproduction of fungus involved gametes and spores. Homothallic :Sexually-compatible gametes are formed on the same mycelium. Heterothallic : require outcrossing between different,yet compatible mycelia.
10) Sexual spores types: Zygospores ( spores enclosed in a thick wall), Ascospores ( spores prodeced by ascus) and Basidiospores (formed externally at a base of basidium).
11) Summary of the life cycle of fungi:
Asexual reproduction: Mycelium undergo mitosis to produce haploid spore-producing structure. This structure later on produce haploid spores to germinate.
Sexual reproduction: Mycelium first undergoes plasmogamy (cytoplasmic fusion) then karyogamy ( nuclear fusion). Between plasmogamy and karyogamy is dikaryotic stage (n+n). After karyogamy, diploid zygote undergo meiosisto produce haploid spore-producing structure. This structure will produce haploid spores to germinate later.
12) Fungi consist of 5 phyla:

  • Chytridiomycota ( cannot see with naked eye)
  • Zygomycota ( mostly mycorrhizae)
  • Ascomycota
  • Basidiomycota ( mostly mycorrhizae)
  • Microsporidia
13) The example of chytridiomycetes is anaerobic rumen fungi. They are neocallimastigales, obligate anaerobes. They can decompose cellulose, break sown lignin deposits into smaller pieces and produce zoospores.
14) In Zygomycota, most of the Fungi are decomposers and mutualists (mycorrhizae). They form coenocytic hyphae, zygosporangia. The example of zygomycota is Rhizopus stolonifer, the bread mold which under genus Rhizopus.
15) Glomeromycota comsidered zygomycetes by some . They form intracellular associations within roots for almost all herbaceous plant and tropical plants.
16) Zygomycota and chytridiomycota are paraphyletic.
17) Ascomycetes are sac fungi, human and and plant pathogens. They produce conidia in asexual reproduction and form ascus with ascospores in sexual reproduction.
18) Genus aspergillus is one of the genus of ascomycetes. They are ubiquitous and they can cause aspergillosis.
19) The another example of ascomycete is Claviceps purpura. C.purpura is parasite on higher plants and they can cause ergotism. Ergotism is the effect of long term ergo-poisoning due to the ingestion of alkaloids that produce by C.purpura that infects rye and other cereals.
20) In Basidiomycota, basidiomycetes are club fungi and they produce basidiospores. They are decomposers and some of the mushrooms are edible.
21) Urediniomycetes and Ustilaginomycetes are the classes under Basidiomycota and they are dimorphic and some of them are human pathogens.
22) Microsporidia are obligate intracellular fungi parasites that infect insects, fish and humans. They contain chitin, trehalose, mitosomes but lack mitochondria, peroxisomes and centrioles.
23) Mycorrhizae is the mutualistic association between plant root and fungi. This association can increase the surface area and growth potential for plant while fungi can feed from tissues of the plant.
24) Lichens are mutualistic relationship between algae and fungi. The algae produce food and the fungus provides protection, water and minerals.
25) There a 3 types of lichens:
  • Foliose lichens: leaf-like
  • Fruticose lichens: hair-like
  • Crustose lichens: grow flat to the surface
26) The fungus in lichens is called mycobiont and the photosynthesizing organism is called a photobiont. Most of the photobiont are algae. Mycobiont adsorb nutrients and photobiont synthesize organic nutrient from carbon dioxide.
27) Yeast under Ascomycota and Basidiomycota. Yeast reproduce asexually by budding, and few by binarry fission. The famous yeast to make bread is Saccharomyces cerevisiae.
28) Dimorphic Fungi undergo dimorphism which is the two form of growth either as mold or yeast.

Activities: Algae and Fungi Crossword.

My Own Explorace:
1) Eumycota means true fungi. It is to differentiate from myxomycota (fungus like slime mold) .
2) Is any fungus exist in the desert? Yes, it is. Desert fungi create symbionts with other host to ensure survival. They resistant to high temperature, dryness and low nutrition. The genus Coccidioides is a soil fungus that live in desert. Each species create hyphae and spore in the soil. After the spores being disturbed by dust storm, the spores are air-borne. People that inhale the spores may causes Coccidiodomycosis (valley fever).body. Cutaneous mycoses: These diiseases extend deep into the epidermis such as hair and nails.
3) Mycosis are diseases that causes by fungus. Subcutaneous mycoses: These kind of diseases may infect dermis, muscle and fascia. Systemic mycoses: These kind of diseases can affect all over the Superficial mycoses: These disease affect the skin of young people.
4) Aerial mycelium : The portion of mycelium that grows upward or outward from the surface of the subtrate.
5) Coenocytic means multinucleated.
6) Dikarya is the subkingdom of Fungi that includes the phyla Ascomycota and Basidiomycota, both which in general produce dikaryons.
7) Paraphyletic means having the same ancestor.
8) These are the truffles.


9) Conidia are asexual spores that usually form at tip or side of hyphae.
10) Obligate refers to parasites that cannot complete its life cycle without exploiting a suitable host.
11) Cryptococcosis is the most common fungal disease in HIV-infected person and it is the AID-defining illness for 60%-70% of HIV-infected patients.
12) Vampyrellids (vampire amoeba) are predators of fungi because it can detroy the fungi by making holes on Fungi.

Reflection:
I learned a lot from the preparation until the exhibition day of Thank A Microbe. First, I learned how to design poster using power point in A1 size and how to create video by adding background description. I felt lazy to go Bukit Expo because Bukit Expo is far away from my kolej. Due to this project, I have a chance to re-visit Bukit Expo to capture our video. My members and I were having a lot of fun there. Besides that, my group members and I worked together so well. Due to this project, we knew about each other more well and I really appreciate the efforts they did to make this exhibition success. Finally, I learned that preparation is important. I thought I had done enough research and preparation for the presentation. Unfortunately, we can't answer the questions from the judges. I felt not satisfied about this. I think we can do better when facing the questions from the judges. Last, I would like to thanks Dr.Wan for guiding us along the preparation until the exhibition day. Thanks for giving a chance to do this challenge and we did it ! For the fungi lecture, there are a lot of terms that I really not familiar with. I will try my best to understand the terms and memorise the terms.

No comments:

Post a Comment