Bio 250 lab quiz 1 Questions With Complete Solutions

Bio safety levels (BSL) measure what? correct answer: an organisms controllability, infectivity, virulence, pathogenicity, antibiotic resistance, vaccine, treatment, mortality. BSL 1 correct answer: does not normally cause disease in people BSL 2 correct answer: Associated with disease BSL 3 correct answer: indigenous/exotic agents that may have serious or lethal consequences and with potential for aerosol transmission BSL 4 correct answer: dangerous/exotic agents of a life-threatening nature or unknown risk of transmission Containment correct answer: safe methods and procedures to handle micro organisms Aseptic technique prevents contamination of correct answer: You Others Experiment Work Area External Enviroment Ubiquitous correct answer: found everywhere Pathogen correct answer: micro organisms that cause disease Opportunistic pathogen correct answer: cause disease in right circumstances Inoculation correct answer: implantation of micro organisms on or in media Culture correct answer: cultivation of the micro organisms What has actually grown Turbid correct answer: cloudy inoculation of growth Colony correct answer: A discrete mass of millions or more cells ideally from one cell Points of first few labs correct answer: practice aseptic technique Sterile correct answer: completely free of all life Pure culture correct answer: one type of colony Mixed culture correct answer: more than one type of colony Parfocal correct answer: once its in focus it stays in focus as you move un in magnification Parcentric correct answer: What is in the center will stay in the center Why is oil needed for high magnification correct answer: oil is needed to refract light the same as glass does 4x correct answer: scanning 10x correct answer: low power 40x correct answer: high power (high dry) 100x correct answer: oil imersion Total magnification correct answer: ocular magnification X objective magnification Working distance correct answer: space between slide and lens As magnification increases field of view.... correct answer: decreases Resolution correct answer: clarity of an image produced by a set of lenses Resolving power correct answer: ability of a lens to separate tow objects in a microscopic field Function of wavelength of light and a property of the lens called numerical aperture Numerical aperture correct answer: mathematical expression that describes the ability of the condenser lens to concentrate light rays from the light source Some refracted light is always lost What are the four factors for maximum resolution and adequate contrast correct answer: Blue filter Condenser position Diaphram position Immersion Oil What does a three lens system consist of? correct answer: Occulars Objectives Condenser Blue filter function correct answer: shorter wavelength Condenser highest position correct answer: limit light lost Diaphram not completely closed correct answer: improves contrast but reduces NA immersion oil correct answer: forms continuous lens system Characteristics of bacterial colonies correct answer: smaller shiner more numerous Molds correct answer: larger (diffuse) fuzzy Chromogenesis correct answer: Production of a color pigment usually via enzyme activity Opacity correct answer: amount of light that can go throughq Opaque correct answer: no opacity Translucent correct answer: some opacity Transpatrent correct answer: opacity What are the three components to shape correct answer: Congifuration, margin, and elevation Texture correct answer: Dry, moist, or mucoid (capsules) Surface appearance correct answer: smooth, rough, dull, wrinkled, shiny Pathogen correct answer: microorganism that causes disease Opportunistic pathogen correct answer: can cause disease in right circumstance Inoculation correct answer: implantation of microorganisms on or in media Culture correct answer: cultivation of the microorganisms, what has actually grown Bacteria colonies correct answer: smaller shinier more numerous Mold colonies correct answer: defuse (larger) fuzzy Aseptic Technique correct answer: No contaminating microorganisms are introduced into culture or culture materials Microbiology is not contaminated by culture that are being manipulated Pure culture technique correct answer: 1. Mix of cells in sample 2. Separation of cells by spreading or dilution on agar medium 3. Growth increases the number of cells 4. Microbes become visible as isolated colonies containing millions of cells How do you calculate total magnification correct answer: Ocular magnification x objective magnification What is the relationship between working distance and magnification? correct answer: Working distance decreases as magnification increases field of view correct answer: what you are looking at What is the relationship between field of view and magnification correct answer: magnification increases as field of view decreases Resolving power correct answer: quantifiable means of measuring the ability of a lens system to resolve detail Chromogenesis correct answer: production of a color pigment usually via enzyme activity Opacity correct answer: amount of light transmitted through Opaque (opacity) correct answer: none Translcuent (opacity) correct answer: some Transparent (opacity) correct answer: almost see through Pigmentation is influenced by correct answer: media, temperature, time Enzyme correct answer: affects organisms metabolism Low temperature correct answer: microbistatic Low temperature effects on organisms correct answer: Reduces Rnx rate membrane fluidity decreases can denature proteins usually doesn't kill slows down high temperatures correct answer: microbicidal High temperature effect on organisms correct answer: denaturation destruction of lipids (archaea and enzymes used in PCR) Thermostability correct answer: ability to maintain structure and or function at high temperatures Psychphiles correct answer: really cold 5-15C Mesophiles correct answer: 15-45C (human pathogens) Thermophiles correct answer: 45-80 (Compost heap) Hyper thermophiles correct answer: 80C (hot springs, archaea) Psychotrophs correct answer: 5-30C Food preservation correct answer: refrigerate 40C freeze Disease correct answer: mesophiles microenviroments human Clostridium botulinum correct answer: spores toxic produced by vegetative cells Release of acetylcholine from motor neurons Flacid paralysis Respiratory failure Obligate Aerobes correct answer: needs oxygen Aerobic respiration Micraerophiles correct answer: stomach 2-10% Aerobic respiration at lower levels Facultative Anaerobes correct answer: Can use oxygen but does not need it can grow in absence of O2 Aerotolerant Anaerobes correct answer: indifferent to O2 O2 does not kill it Obligate fermentor obligate Anaerobes (chlostritium) correct answer: O2 is toxic will kill it does not use O2 Anaerobic respiration Fermentation Fluid thioglycollate medium (FTM) correct answer: rich liquid + a little bit of agar thioglycollate correct answer: reduces oxygen to water Rasazurin dye correct answer: pink in O2 Methylene blue correct answer: blue in presence of O2 White in absence of O2 Lethal effects of light on bacteria correct answer: sterilizes surfaces lethal effects due to mutagenetic properties 260nm (max killing) Why is UV most effective at killing bacteria 260nm correct answer: DNA absorbs the most pyrimidine dimers Microcaccus Lubous correct answer: obligate aerobe Serratia marcessens correct answer: facultative anaerobe Enterococcus farcalis correct answer: facultative anaerobe alcaligenes faccalis correct answer: obligate aerobe Costridium sporogenes correct answer: obbligate anaerobe Aerobic respiration correct answer: O2 used as a terminal electron acceptor converted to H2O H2O2 is a by-product correct answer: oxidizing agent damages RNA, DNA, proteins What do anaerobes and aerotolerant anaerobes lack correct answer: catalase