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Parasitology
Foundations of Parasitology
Question | Answer |
---|---|
What is symbiosis? | Living together. |
What are 3 major types of symbiosis? | Commensalism, mutualism, parasitism. |
Describe parasitism. | Type of symbiosis in which the parasite lives at expense of the host. |
Describe mutualism. | Type of symbiosis in which both benefit from the relationship. |
Describe commensalism. | Type of symbiosis in which one partner benefits and niether is harmed. |
What is phoresis? | Two symbionts traveling together. Ex. Bacteria on legs of a fly. |
What is a vector? | Anything that transmits disease to an organism. |
What is facultative? | When a parasite can live within the host or outside of the host in the same environment. |
Obligate parasite | Describes a type of parasite that cannot complete their life cycle without spending at least part of the time in a parasitic relationship. |
Accidental or incidental parasite | When a parasite enters or attaches to the body of a species of host different from its normal one. |
Micropredator | Parasites that usually prey on several different hosts (or the same host at several discrete times). |
Parasitoid | A parasite that spends a significant portion of its life on or within one host ultimately killing it. Ex. wasp or fly. |
Protelean parasite | Are insects in which which only the immature stages are parasitic. |
Difinitive host | A host in which the parasite reaches sexual maturity. |
Intermediate host | A type of host that is required for parasite development, but the parasite does not reach sexual maturity. |
Paratenic or transport host. | One in which the parasite does not go through any development but it remains alive and infective. |
Reservoir host | Any animal that harbors infection that can be transmitted to humans. Ex. Trichnella spiralis, Leishmania spp., Trypanosoma cruzi. |
Hyperparasitism | Parasites hosting other parasites. |
Histozoic | Parasites living within tissues. |
Coelozoic | Parasites living in the lumen of the intestine or other hollow organs. |
Ectoparasite | A parasite that lives outside of its host. |
Endoparasite | A parasite that lives within its host. |
Invasiveness | The degree to which an organism can infect its host. |
Infectivity | The ability of a parasite to enter, reproduce and infect its host. |
Virulence | The degree or ability to which a pathogen can cause disease. |
Infrapopulation | All individuals of a single parasite within a host. |
Metapopulation | All the infrapopulations in a single host species in an ecosystem. |
Suprapopulation | All the parasites of a species regardless of their developmental stage in an ecosystem. |
Prevelance | Fraction or percentage of a single host species infected at a given time. |
Nidus/Focus | This is the specific location of a disease. It is the set of ecological conditions that must be in place for the disease to occur. |
Plasma membrane | A lipid bilayer that covers protozoa. |
Pellicle | Thin translucent secreted envelope covering many protozoa. |
Alveoli | Pockets or spaces bounded by membrane. |
Glycocalyx | A glycoprotein surface on protozoa which has immunological importance. |
Undulating membrane | 1. In some flagellates, a finlike ridge across the surface of a cell, with the axoneme of aflagellum near its surface. 2. In some ciliates it is a line of cilia that are fused at their bases, usually beating to force food particles the gullet. |
Golgi apparatus | Eukaryotic cell organelle that acts as a post office, packaging and labeling items and sending them on there way. |
Parabasal bodies/Kintesomes | It is found at the base of a eukaryotic undulipodium (cilium or flagellum) and serves as a nucleation site for the growth of the axoneme microtubules |
Endosomes | A membrane-bound compartment inside eukaryotic cells. It is a compartment of the endocytic membrane transport pathway from the plasma membrane to the lysosome. |
Mastigonemes | Hair like structures on flagella. May help with locomotion. |
Mastigont system | In flagellates the mastigont system is usually a single unit comprised of the flagella with their basal bodies, the flagellar roots attached to the basal bodies, and the centrosomal structures associated with the basal bodies. |
Kintoplast | A disk-shaped mass of circular DNA inside a large mitochondrion that contains many copies of the mitochondrial genome and are only found in protozoa of the class Kinetoplastida. |
Contractile vacuole | Organelle that removes excess water from the cell, especially protozoans. |
Kineties | Row of cilia basal bodies and their kinetodesmose . All kineties and kinetodesmata in the organism are its infraciliature. |
Infraciliature | All cilia, basal bodies, and theirassociated fibrils in a ciliate protozoan. |
Oral ciliature | Cilia that is associated with the protozoan mouth. It usually includes poleukinetids and membranes. |
Cirri | Fused tufts of cilia in some protozoan like tiny legs. |
Pseudopodia | Temporary extensions of the cell membrane of ameobas. Functions are locomotion and feeding. |
Amebastomes | The suckerlike structures found on protozoa that function in phagocytic feeding. |
Protozoan cyst | Protozoans secrete a resistant covering and enter a resting stage or cyst. This occurs to protect protozoan from undesirable conditions. |
Describe protozoan nutrition | Protozoa are usually particle feeders...grazers and predators. Symbionts feed on their host. |
Heterotroph | A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. |
Autotroph | An autotroph, or producer, is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple inorganic molecules using energy from light (by photosynthesis) or inorganic chemical reactions (chemosynthesis). |
How do heterotrophs feed? | Heterotrophs feed by capturing by engulfment or cytostome...Endocytosis. |
Cytosome | A cytostome or cell mouth is a part of a cell specialized for phagocytosis, usually in the form of a microtubule-supported funnel or groove. |
Endocytosis | Protozoan feeding by way of pinocytosis and phagocytosis. |
Pinocytosis | Protozoan taking up water droplets. |
Phagocytosis | Protozoan taking up or internalizing particulate matter. |
Parasitophorous vacuole | A vacuole formed by host cell made of layers of endoplasmic reticulum around an intracellular parasite which in some cases may serve to isolate the parasite to lyse. The host cell may provide the parasite with nutrients. |
Lobopodia | Finger shape round tipped pseudopodia that contain endoplasm and ectoplasm. |
Filopodia | Slender sharp pointed organelles composed ONLY of endoplasm. |
Rhizopodia | Organelles which branch extensively and may fuse together to form netlike meshes. |
Axopodia | Like filopodia, but each contains a slender axial filament composed of microtubles that extends into the interior of the cell. |
What are the 5 types of antibodies? | IgM (Immunoglobin M), IgG (Immunoglobin G), IgA (Immunoglobin A), IgD (Immunoglobin D), IgE (Immunoglobin E) Gmu, gamma, alpha, delta, epsilon |
Describe basic antibody molecule structure. | 4 polypeptide strands: 2 heavy and 2 light chains, helded together like a Y with disulfide and hydrogen bonds, amino acide sequence at end of Y=variable region. End of Y=cleft that acts as antigen binding site. |
How does the ELISA (Enzyme-linked immunosorbent assay) work? | Known antigen adsorbed to bottom of test well, serum added ,rinse, add enzyme-linked ab against human immunoglobulin, rinse, add enzyme substrate, observe for color change products=presence of bound anti-Ig, so presence of ab against antigen, POS test |
Antigen | A foreign substance in body. |
Antigen presenting cell (APC) | Cells (i.e. macrophages) that present epitopes of antigens on their surface, in the cleft of MHC II proteins, which causes the activation of appropriate T cells. |
Epitope | The portion of the antigen presented on the surface of the APC. |
Challenge dose | Another dose of antigen administered later after an initial immunizing dose. |
Macrophage | A monocyte that differentiates into a phagocyte and migrates to lymph nodes, spleen and lung. |
Killer T cell | A lymphocyte like cell that can kill virus infected and tumor cells in the abscence of the ab. They lyse. |
Cytotoxic T lymphocyte (CTL) | C8D+ T cells that bind to and destroy target cells displaying certain antigens. |
Complement | Series of proteins that bind in a complex series of reactions to antibody (IgM or IgG when the antibody is itself bound to an antigen, produces lysis of cells if the antibody is bound to antigens on the cell surface. |
Antigen variation | A mechanism used by parasites to evade immune response. The antigen alters its surface protein. |
Binary fission | Asexual reproduction. Mitotic division of a single cell into two single cells. Ciliates use transverse while flagellates use longitudinal |
Multiple fission (schizogony, merogony) | Asexual reproduction. Division of the nucleus into daughter cells followed by division of remainder of cell before cytokinesis. |
Polyembryony | Development of two or more offspring from a single zygote. |
Sexual reproduction | Male and female union to produce offspring. |
Internal budding (endopolyogeny) | Daughter cells begin forming within their own cell membraines,distributed throughout the mother cell's cytoplasm rather then at the periphery. |