Chapter 12 - Eukaryotic Microbes Flashcards
What is a protozoa?
An organism that reproduces asexually through fission, budding, or shizogony. Has 200,000 species, Divided into Clades.
There are Excavata, Euglenozoa, amebae, apicomplexa, and ciliates
Excavata
lack mitochondria, move by flagella or undulating membranes. Examples include Giardia, trichomonas, and trichonympha
Euglenozoa
Move by flagella, are hemoflagellates. Examples include Trypanosoma.
Amebae
move by pseudopods, and an example is entamoebae histolytica
Apicomplexa
In definitive host, it sexually reproduces. In an intermediate host, there is asexual reproduction. An example is Plasmodium Vivax
Ciliates
They move by cilia and are rarely pathogenic. An example is Paramecium
Differentiate between Intermediate host and definitive host
The intermediate host is where the parasite undergoes asexual reproduction ( us the human with plasmodium vivax/malaria)
The definitive host is where the parasite reproduces sexually.
Cellular Slime Molds
Eukaryotic cell that resembles amebae. During the life cycle, cellular slime molds live and grow by ingesting fungi and bacteria by phagocytosis. When things get rough, cellular slime molds come together as one large structure, but germinate when things are ok again.
Plasmodial Slime Molds
Exists as a mass of protasm with many nuclei called a plasmodium. Moves as a giant amebae, engulfs organic debris and bacteria. Changes speed and direction to evenly disperse nutrients.
Common features of Algae
all are photosynthetic, mostly aquatic, all can reproduce asexually. Heterogeneous features: some single celled, some multicellular. Some can reproduce sexually as well as asexually
Brown Algae
Multicellular, includes kelp, produce algin (a food thickener)
Red Algae
Most are multicellular, Produce Agar
Green Algae
Unicellular and multicellular; probably gave rise to terrestrial plants.
Diatoms
Unicellular; produce toxins that are concentrated in shellfish and fish that ingest them.
These toxins cause disease in humans. Example: paralytic shellfisch poisoning etc.
What is Lichen, How do the two parts support each other?
Lichen is algae wrapped fungus. The fungi protects the algae, and the algae takes in sunlight to make sugars for the fungi.
How are fungi differentiated from other eukaryotes?
Fungi are chemoheterotrophs, absorb nutrients, can tolerate a pH of 5, are aerobic, can grow in dry places (resistant to osmotic pressure), and have low moisture.
Mold
Multicellular; have hyphae that look for nutrients.Septate have cross walls dividing the hypahe into cell like units. Coenocytic lack septa. Hyphae grow by elongating at the tips.
Yeast
Single celled, divide by binary fission or budding, dimorphism (can be male/female)
Sexual Reproduction in Fungi
Two different haploid mating types:
- Plasmogymy: two haploid cells fuse
- Karyogomy: nuclei fuse, results in diploid reproductive structure.
**meiosis results in haploid spores
Zygomycota
Reproductive Structures: zygospore, sporangium. Example: rhizopus
Ascomycota
she has sexual and asexual lifestyles. Sexual=saclike ascus (ascospores); asexula=condida (spores)]These cause plant and human diseases.
Basidiomycota
Life Cycle: asexual - hyphae fuse to form myceia, sexual =club shaped bacteria; examples= mushrooms and cryptococcus neoformans
What is deuteromycota and why it is not a phylum
artificial catch all; nor reproductive structure (anamorphs) most currenlty classified as ascomycota
Fungi and human disease
Immune response
- Mycotoxin
- Infection
Mycoses
why are some fungal infections in humans difficult to treat?
Because drugs that affect fungal cells, may also AFFECT ANIMAL CELLS.
