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109 Cards in this Set
- Front
- Back
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What is a glycocalyx?
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An outermost boundary that comes into direct contact with the environment.
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What composes the glycocalyx?
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It's compose of polysaccharides and appears as a network of fibers, a slime layer, or a capsule much like of a glycocalyx of the prokaryotes.
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What are the functions of glycocalyx?
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It promotes adherence to environmental surfaces and the development of biofilms and mats. It also serves as important receptor and communication functions and offers some protection against environmental changes.
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What is the layer beneath the glycocalyx of fungi and most algae?
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Thick, rigid cell wall sorrounding the cell membrane.
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What is the layer beneath the glycocalyx of protozoa, some algae and animals?
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The lack cell walls and are encased primarily by a cell membrane.
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What are the two groups of fungi? Give examples of each.
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Macroscopic - mushrooms, puffballs, gill fungi
Microscopic - molds and yeast |
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What are the two basic morphological types of fungi?
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Hyphae and Yeast
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What is a hyphae?
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It's a long threadlike cells that make up the bodies of filamentous fungi, or molds.
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What is a yeast?
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Cell is distinguish by its round to oval shape and by its mode of asexual reproduction. It grows swelling on its surface, called buds, which then become a separate cell.
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What is pseudohypa?
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A chain of yeast formed when buds remain attached in a row.
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Why is pseudohypa considered NOT a true hypha like those of the molds?
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Because of their manner of formation.
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What is dimorphic?
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They can take either form, depending on the growth conditions such as temperature change.
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What are the chemical traits of fungi?
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Posession of polysaccharide called chitin in their cell wall, sterol and ergosterol in their cell membrane.
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What is mycoses?
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Fungal infections in animals.
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How do fungi get their nutrition?
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By being heterotrophic, Saprobes and Parasites.
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What is heterotrophic fungi?
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Acquire nutrient from a wide variety of substance or substrate.
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What are saprobes?
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They acquire nutrients from the remnants of dead animals and plants in soil or aquatic habitats.
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What are parasitic fungi?
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Parasitic fungi are on the bodies of living animals or plants, although a very few fungi absolutely require a living host.
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How does a fungus operate in general?
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Fungus penetrates the substrate and excrete an enzymes that reduce it to small molecules that can be absorbed.
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What are the types of Asexual Spore formation?
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Zygospores and Conidium
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What is a zygospore?
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Formed by successive cleavages within a sac like head called sporangioum, attached to a stalk called sporangiophore. These spores are initially enclosed by are released when the sporangium ruptures.
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What is a conidium?
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Are free spores not enclosed by a spore-bearing sac. They develop either by pinching off by a special fertile hypha or segmentation of a preexisting vegetative hypha.
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What are the common forms for conidia?
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Arthrospore, Chlamydospore, Blastospore, Phialospore, Micronidium and Macronidium and Porospore
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What is arthrospore?
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A rectangular spore formed when a septate hypa fragments at the cross walls.
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What is chlamydospore?
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A spherical conidium formed by the thickening of the hyphal cell.
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When do chlamydospore get released? And for what purpose?
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They get released when the sorrounding hypha fractures and it serve for survival or resting cell.
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What is blastospore?
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A spore produced by budding from a parent cell that is a yeast or conidium, also called bud.
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What is phialospore?
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A conidium budded from the mouth of a vase-shaped spore-bearing cell called phialide or sterigma, leaving a small collar.
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What is micronidium and macronidium?
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smaller and larger conidia formed by the same fungus under varying condition. Micronidia are one-celled. Macronidia have two or more cells.
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What is a porospore?
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A conidium that grows out through small pores in the spore-bearing cell; some composed of several cells.
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What are the common sexual spores?
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Zygospores, Ascospores and Basidiospores
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What are zygospores?
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Sturdy diploid spores formed when the hyphae of two opposite strains (plus and minus strains) fuse to create a diploid zygote that swells and becomes covered by a strong spiny walls.
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How does a sporangium develop?
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When its wall is disrupted, mositure and nutrient conditions are suitable, the zygospore germinates, and forms a mycelium, which gives rise to a sporangium.
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Meiosis of diploid cells of the sporangium results in what?
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Haploid nuclei that develop into sporangiospores.
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The sporangiosphores from sexual process and asexual process are identical, how can they be different?
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Sporangiospores from sexual process are genetically different to those from asexual process because they arose from the union of two separate fungal parents.
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What is a ascospores?
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Haploid spores, created inside a special fungal sac or ascus.
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How do ascus and ascospores formed?
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When different strains or sexes join together to produce offspring.
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What are dikaryons?
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It's a number of terminal cells, which is the end result of the formation of ascospore, each containing a diploid nucleus.
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How does ascospore cell enlarges to form an ascus?
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Through differentiation. Its diploid nucleus undergoes meiosis (often followed by mitosis) to form four to eight haploid nuclei tha t will mature into ascospores.
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What are Basidiospores?
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Haploid sexual spores formed on the outside of club-shaped cell called basidium.
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What is Aspergillus flavus? And what does it toxin do?
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A mold which synthesizes a potentially lethal poison called aflotoxin. The toxin causes a disease in domestic animals that have eaten grain contaminated with the mold and also causes liver cancer in humans.
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What are mycorrhizae?
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Stable associations with plant roots that increase the ability of the roots to absorb water and nutrients.
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What are saccharomyces?
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Yeast, which produces alcohol in beer and wine; the gas that causes bread to rise.
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What are algae?
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Photosynthetic organisms, varies in length from few mm to 100 m, occur in unicellular, colonial, and filamentous forms, and the larger forms can possess tissues and simple organs.
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What are diatoms?
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Single-celled chrysophyta; have silicate cell walls and golden pigment in their chloroplast.
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What are prototheca?
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An unusual non-photosynthetic alga associated with skin and subcutaneous infections in humans and animals.
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What are dinoflagellates?
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Toxic marine algae, which causes red tide.
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How do we get affected by dinoflagellates? What are the symptoms associated?
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Paralytic shellfish poisoning is caused by eating exposed clams or other invertebrates and is marked by neurological symptoms and can be fatal.
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What is Ciguatera?
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Serious intoxication caused by algal toxins accumulated in fish such as bass and mackerel.
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What is Pfiesteria piscicidia?
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toxic algal form, which causes fish and humans develop neurological symptoms and bloody skin lesions.
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What are protozoa?
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Unicellular eukaryotic protists that lack tissues and share similarities in cell structure, nutrition, life cycles, and biochemistry - most of them are motile.
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What are the two division of cytoplasm in protozoans? Describe each.
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Ectoplasm - clear outer layer; involved in locomotion, feeding and protection.
Endoplasm - granular inner region; houses the nucleus, mithocondria, food and contractile vacuole |
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What consititutes to the flexibility of protozoans?
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Lack of cell wall
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What is the function of the outer boundary of protozoans?
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A cell membrane that regulates the movement of food, wastes and secretion.
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What are the sizes of protozoans?
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Most protozoan cells falls within the range of 3 to 300 mm. Giant amoebas and ciliates 3 to 4 mm to be seen swimming in pond water.
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What's the difference in cell shape between ciliates, amoebas and foraminiferans?
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Ciliates - cell shape remain constant; amoebas - changes constantly; foraminiferans encase themselves in hard shells made of calcium bicarbonate.
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What is a trophozoite?
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Motile feeding stage; requires ample food and moisture to remain active
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What is a cyst?
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Dormant, resting stage when conditions in the environment become unfavorable for growth and feeding.
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What is encystment?
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Trophozoite cell rounds up into sphre, and its ectoplasm secretes a tough, thick cuticle around the cell membrane.
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What dictates the protozoan mode of transmission to other hosts?
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Life cycle of parasitic protozoans
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What is Trichonomas vaginalis? How do they get transmitted?
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Causes sexually transmitted disease. It doesn't form cyst and must be transmitted by intimate contact between sexual partners.
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What are examples of intestinal pathogens (protozoans)? How do they get transmitted?
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Entamoeba histolytica; Giardia lamblia. They form cyst and can be transmitted in contaminated food and water.
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What are the medically important protozoans?
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The Mastigophora (Zoomastigophora), The Sarcodina (Amoebas), The Ciliophora (Ciliates) and The Apicomplexa (Sporozoa)
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What is Mastigophora?
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Single nucleus; motility is primarily by flagella alone or by both flagellar and amoeboid motion; sexual reproduction by syngamy, division by longitudinal fission; several parasitic forms lack mitochondria and Golgi Apparatus; Most species form cysts, free-living, some in loose aggregate colonies but most are solitary.
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What are some of the members of Mastigophora?
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Trypnasoma and Leishmania - blood pathogens spread by insect vectors; Giardia - intestinal parasite spread in water contaminated with feces; Trichonomas - parasite of the reproductive tract of humans spread by sexual contact
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Describe the sarcodina (amoebas)
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Cell form is primarily an amoeba; major locomotor organelles are pseudopods, although some have flagellated reproduction states; asexual reproduction by fission; mostly uninucleate; usually encyst; most are free-living and not infectios
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What is an example of sarcodina?
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Entamoeba - parasite in humans
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What protozoan is responsible for chalk deposits in the oceans?
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The sarcodina - shelled amoebas called foraminifera and radiolarians
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Describe Ciliophora.
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Motile by cilia; some have cilia in tufts for feeding and attachment; most develop cyst; have both macronuclei and micronuclei; division by transverse fission; most have definite mouth and feeding organelle; free-living and generally harmless.
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What is the one pathogen for ciliophora?
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Balantidium
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Describe The Apicomplexa.
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Motility is absent, except male gametes; complex life cycle with well-developed asexual and sexual stages; most form thick-walled zygotes called oocysts; entire group is parasitic
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What is the most prevalent protozoan parasite?
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Plasmodium - causes malaria; 100 to 300 million cases worldwide
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Examples of the apicomplexa
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Plasmodium, Toxoplasma gondii; Crytosporidium
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What is Toxoplasma gondii?
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Causes acute infection (toxoplasmosis) in humans, which is acquired from cats and other animals
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What is Crytosporidium?
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An emerging intestinal pathogen transmitted by contaminated water.
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What's the difference in locomotion between mastigophora, sarcodina, ciliophora and apicomplexa
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Mastigophora - flagella or both flagella and amoeboid motion
Sarcodina - major locomotor organelles are pseudopods, although some have flagellated reproduction state Ciliophora - through ciliates Sporozoa - motility is absent, except male gametes |
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Describe the different reproduction between mastigophora, sarcodina, ciliophora and apicomplexa.
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Mastigophora - syngamy,division by longitudinal fission;
Sarcodina - asexual reproduction by fission Ciliophora - Division by transverse fission Apicomplexa - Well-developed sexual and asexual stages |
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What do sporozoans produce after sexual reproduction?
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Sporozoites
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Why is sporozoites important?
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Transmission of infections
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What are the common representatives of genus Trypanosoma?
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T. brucei and T. cruzi
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What causes Chaga's disease?
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T. cruzi
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T. cruzi, which causes Chaga's disease, relies on what?
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Close relationship of warm-blooded mammal and insect that feeds on mammalian blood.
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What are the mammalian hosts for T. cruzi?
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dogs, cats, opossums and armadillos
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What is the vector for T. cruzi?
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reduviid bug (kissing bug)
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Why is reduviid bug called the kissing bug?
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Because of its habit of biting its hosts at the corner of the mouth.
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How does T. cruzi get transmitted?
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Transmission occurs from bug to mammal, mammal to bug, but never from mammal to mammal, except across the placenta during pregnancy.
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What is the transmission cycle of T. cruzi?
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Trypanosome trophozoite multiplies in the intestinal tract of the reduviid bug and is harbored in the feces.
The bug seeks a host and bites the mucous membranes, usually of the eye, nose or lips, releasing the trypanosome in feces near in the bite. Victim scratch the bite, which contribute to the entry of the microbe. Once in the body, multiply in muscle and white blood cells. Periodicall, these parasitized cells rupture, releasing large numbers of new trophozoites into the blood - spread into systems such as lymphoid organs, heart, liver and brain. |
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How do victims contribute to the entry of the microbe T. cruzi?
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By scratching the bite wound
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What are the symptoms of Chaga's disease (T. cruzi)?
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Ranges from mild to severe - fever, inflammation, heart and brain damage- extended course can cause death.
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What causes amebic dysentery?
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Entamoeba histolytica
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What is the important stage for transmission for entamoeba?
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Cyst because its more resistant and can survive in water and soil for several weeks.
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How do people get infected by Entamoeba?
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Ingesting food or water contaminated with human feces.
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Describe the amebic dysentery cycle.
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Start with the ingestion of the cysts, which passes through the stomach unharm because they're heavily-walled. Once inside the small intestine, the cyst germinates into large multinucleate amoeba that subsequently divides to form small amoebas; migrates to large intestine and begin to feed and grow; penetrate the lining of the intestine and invade the liver, lungs and skin. then trophozoites pass out of the body through fecal matter.
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What is the trophozoite stage?
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When the cysts germinates into a large multinucleate amoeba that subsequently divides to form small amoebas.
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When is the cycle of trophozoite get completed in humans?
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The cycle is completed in infected humans when certain trophozoite s in the feces begin to form cysts, which then pass out of the body with fecal matter.
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What are the symptoms for amoebic dysentery?
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Gastrointestinal disturbances such as nausea, vomiting, and diarrhea. leading to weight loss and dehydration.
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What are the preventative measures for Entamoeba?
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Sewage treatment, curtailing use of human feces as fertilizer, and adequate sanitation of food and water.
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What are helmiths?
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Tapeworms, flukes and roundworms.
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What are the sizes for tapeworms and roundworms?
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Tapeworms - measuring up to 25 mm in lenght
Roundworms less than 1 mm in length |
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What are the two major groups of parasitic helmiths?
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Flatworms - Phylum Platyhelminthes; Roundworms - Phylum Aschelmithes
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What are flatworms?
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Very thin, often segmented body plan
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What are the two kinds of flatworms?
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Cestodes - tapeworms named theri long, ribbon like arrangement
Trematodes - or flukes, characterized by flat ovoid bodies |
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What are roundworms?
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Also called nematodes - with an elongate, cylindrical, unsegmented body
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What is Enterobius vermicularis?
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Pin worm or seatworm; causes infestation in large inestestine; range from 2 to 12 mm long and have a tapered, curved cylinder shape, causes enterobiasis, uncomplicated infection that does not spread beyond the intestine
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Describe the cycle of a pinworm.
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The cycle starts when a person swallows microscopic eggs picked up from another infected person by direct contact or by touching contaminated surfaces. The eggs hatch in the intestine and tehn release larvae that mature into adult worms within one month. Male and female worms mate, and the female migrates out to the anus to deposit eggs, which causes intense itchiness which is relieved by scratching.
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What is the significant means of dispersal for pinworms?
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Scratching contaminates the fingers, which, in turn, transfers eggs to bedclothes and other inanimate objects. This person becomes a host and a source of eggs, and can spread them to others in addition to reinfesting himself.
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What are the fungi that causes sick building syndrome?
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Aspergillus, Cladosporium and Stachybotyrs
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What are the source of the fungi in sick buidling syndrome?
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Presence of chronically water-damaged walls, ceilings, and other building materials that have come to harbor these fungi.
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What happen to people exposed to houses or buildings contaminated with fungi?
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Report symptoms range from skin rush, fluelike reactions, sore throat, headaches and fatigue, diarrhea, allergies, and immune suppression.
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