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90 Cards in this Set
- Front
- Back
what are the 5 I's of microbiology?
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inoculation, incubation, isolation, inspection, identification
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what does sterile mean?
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the complete absence of viable microbes
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what does aseptic refer to?
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prevention of infection
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what does pure culture refer to?
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growth of a single species of microbe
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what are the three methods of isolating bacteria?
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-streak plate method
-loop dilution / pour plate -spread plate |
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what is the only medium suitable for viral cultivation?
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viruses can only be cultivated in live cells
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what are some examples of different media?
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broth, agar, gelatin, rice grains/cooked meat, etc.
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what are the three physical forms of lab media?
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liquid, semisolid, solid
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what the the two chemical forms of lab media?
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synthetic, nonsynthetic
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what makes non-synthetic media different than synthetic?
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nonsynthetic media cannot be represented by an exact chemical formula and may contain substances such as animal extract, ground up cells, tissues, plant or yeast extract, etc.
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what does is mean for a medium to be synthetic?
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it means it has a chemically defined composition and the exact chemical formula is known.
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what is a general purpose medium?
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designed to grow a broad spectrum of microbes that do not have special growth requirements. this type of media is nonsynthetic (i.e. it is complex)
examples include broth, nutrient agar, and TSA |
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what is an enriched medium?
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a medium that contains complex organic substances such as blood, serum or growth factors.
ex: blood agar |
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what is fastidious bacteria?
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bacteria that require growth factors and complex nutrients.
(enriched medium) |
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what is a selective medium?
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a medium that contains one or more agents that inhibit the growth of a certain microbe or microbes but allows growth of another.
this type of medium is important in primary isolation of a specific type of microbe from a sample contains many- like saliva, soil, etc. |
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what is MSA (mannitol salt agar)?
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a selective medium that has a high concentration of NaCl which inhibits growth of most human pathogens except staphylococcus.
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media for isolating intestinal pathogens contain what?
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bile salts- because bile salts are a component of feces that inhibit most gram-positive bacteria from growing
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methylene blue and crystal violet inhibit what type of bacteria?
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gram positive
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selenite and brilliant green dye are used in media to isolate what?
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salmonella (from feces)
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what is sodium azide used to isolate?
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enterococci (from water and food)
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what is differential media?
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a medium that grows several types of microbes but is designed to bring out visible differences among them via variation is color, colony size etc.
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what is a reducing medium?
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a medium that contains a substance that absorbs and reduces the availability of oxygen. -important for growing anaerobic bacteria or determining oxygen requirements
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what is transport media?
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used to maintain and preserve specimens that have to be held for a period of time before clinical analysis, or for very delicate species that require highly stable conditions.
ex: Stuart's and Annie's transport media |
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what is an assay media?
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used to test effectiveness of antimicrobial drugs, disinfectants, and antiseptics etc.
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what is enumeration media?
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used by industrial and environmental microbiologists o count the number of organisms in milk, water, food, soil, etc.
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what does axenic mean?
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that a culture is free of other living things except for that being studied... AKA a pure culture
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what does it mean to subculture?
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to make a second-level culture from a well isolated colony. -a method to ensure a pure culture.
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what is a mixed culture?
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a container that holds two or more easily differentiated species of microbes
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what are the two key characteristics of a microscope?
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magnification and resolving power
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what does the condenser on a scope do?
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converges, or focuses, rays of light to a single point on the object.
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how is total magnification calculated?
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occular X objective = total magnification
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what forms the "real image" ?
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the objective lens
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what forms the "virtual image" ?
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the ocular lens, which magnifies the real image produced by the objective lens
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what is resolution or resolving power?
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the ability to distinguish two objects from one another
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how is resolving power calculated?
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RP = wavelength of light/ 2x objective lens
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what are the longest and shortest visible wavelengths?
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shortest = violet/blue
longest = red |
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what does the iris diaphragm do?
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controls the amount of light entering the specimen
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what is the category of prokaryotes that has peptioglycan in its cell wall?
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bacteria
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what are the three parts of a bacterial flagellum?
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filament, hook(sheath), basal body
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what are the ways that flagella can be oriented on a bacterium?
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monotrichous- single flagellum at one end
lophotrichous- several on on one end amphitrichous- flagella at both ends poles of cell peritrichous- flagella are dispersed randomly over the surface of the cell |
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what is positive chemotaxis?
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the movement of a cell in the direction of a favorable chemical stimuli. made possible by flagella.
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what is negative chemotaxis?
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movement away from a chemical repellent. made possible by flagella
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what are spirochetes?
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corkscrew shaped bacteria
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what are fimbriae?
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small, bristlelike fibers emerging from the surface of many bacteria that tend to stick to one another on adjacent cells. (biofilms)
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what is a pilus?
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found only in gram negative bacteria where they are utilized in conjugation.
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can gram-positive bacteria perform conjugation?
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no
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what is glycocalyx?
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a coating of macromolecules that protects the bacterial cell and may help it adhere to its environment
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what two forms does glycocalyx come in?
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slime layer and capsule
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do bacteria with glycocalyx slime layers or capsules have greater pathogenicity?
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capsules-protect themselves against phagocytes
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what color do gram positive bacteria stain? gram negative?
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+ : purple
- : red |
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what is the difference between gram positive and gram negative bacterial cell envelopes?
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positive: contains a cell membrane + cell wall composed of peptidoglycan
negative: contains a cell membrane + cell wall composed of peptidoglycan and an additional outer membrane |
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what is lysozyme?
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an enzyme found in tears and saliva that provides a natural defense against certain bacteria by hydrolyzing the bonds in the glycan chains and causing the cell wall to breakdown.
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a prokaryotic cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is what?
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gram-positive (purple)
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what is periplasmic space?
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the space between cell wall and cell membrane in bacterial cells
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gram pos. or neg. contains an outer membrane in addition to cell wall and membrane ?
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negative (red)
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gram pos. or neg. contains lipoproteins and LPS?
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neg.
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what is the composition of bacterial cell membrane?
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lipid bilayer with embedded proteins
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spirochetes typically have what type of flagellum?
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periplasmic flagellum
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what two protein types are found in the outer membrane of gram neg. bacterial cell walls?
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porins and structural proteins
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the lipids in gram neg. bacterial cell wall (OM) are called what?
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endotoxins- because they contribute to fever and shock reactions in gram negative infections like meningitis
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acid-fast staining might be used to detect what..?
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Tuberculosis
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what is acid-fast staining used for?
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bacterial cells with nontypical cell walls that do not stain gram neg. or gram pos.
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what are mycoplasmas?
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bacteria that naturally lack a cell wall
resists lysis via sterol components |
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what are L form bacteria?
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bacteria that have a cell wall but lose it at some point in their life cycle
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the cell membrane can form internal folds called what?
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mesosomes
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mesmosomes are prominent where...?
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in gram positive bacteria (they increase surface area)
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in what form does the hereditary material of most bacteria exist in?
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single, circular strand of DNA called the bacterial chromosome
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what is a nucleoid?
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aggregation of bacterial DNA; as opposed to a true nucleus.
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what are bacterial plasmids?
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nonessential pieces of DNA, not associated with core genetic material found in the nucleoid. responsible for drug resistance, can be incorporated into chromosome.
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what is a bacterial strain? type?
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strain is a culture derived from a single parent that differs in structure or metabolism from other cultures of that species
type is a subspecies that can show differences in antigenic makeup, in susceptibility to bacterial viruses, and in pathogenicity. |
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thylakoids in cyanobacteria contain what ?
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chlorophyl a
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what microorganisms have eukaroytic cells?
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fungi, protists(algae), protozoa, and helminthis
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what eukaryotic cells have a cell wall?
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fungi & algae (protists)
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where are 70s ribosomes found?
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mitochondria
chloroplast prokaryotes |
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where are 80s ribosomes found?
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only in eukaryotic cells (but eukaryotic cells contain both 80s and 70s)
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stacks of thylakoid are called what? where are they found?
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grana... surrounded by stroma. found in plant and algae cells
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what are the two main types of cytoskeletal elements?
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microfilaments and microtubules
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which eukaryotic cells lack a cell wall?
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animal, protozoa, helminthis
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what are the two types of fungi (broadly speaking) ?
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microscopic fungi (molds, yeast) and macroscopic fungi (mushrooms)
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what are hyphae?
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cell type of mold
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what are the two fungal cell types?
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hyphae and yeast
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most fungi are saprobes, which means what?
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that they obtain nutrients from the remnants of dead plants and animals
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what is mycoses?
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fungal infection in animals
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what is a mycelium?
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the intertwining mass of hyphae that makes up the body or colony of mold
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what is the difference between sporangiospores and conidiospores?
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sporangiospores are initially enclosed and realsed when sporangium ruptures.
conidiospores pinch off preexisting vegetative hypha |
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the cytoplasm of protists is divided into what two parts?
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ectoplasm and endoplasm
ectoplasm is implicated in feeding, locomotion and protection. endoplasm houses nucleus, mitochondria and vacuoles |
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what is a mature cyst?
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the dormant, resting stage of protozoa
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how do the protists mastigophora move?
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flagella
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how do the sarcodina (protists) move?
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pseudopods
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how do ciliophora move?
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cillia
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