Micro Lab Exam 1 UTK Questions With 100% Verified Solutions Graded A+.

If an organism is being viewed with the 40X objective lens on a standard bright light microscope, how much is the image you see magnified? I.e. what is total magnification? - correct answers(objective lens magnification)*(10) (40X)*(10) = 400X Define the term microorganism - correct answers A living organism that is physically to small to be seen by the naked eye Morphologies - correct answers shapes given to certain bacteria Coccus (Circular) - correct answers small circular colonies Rod (bacillus) - correct answers long, rod like Spiral (spirillum) - correct answers spiral or corkscrew List characteristics of prokaryotes - correct answers- Have a cell wall made of peptidoglycan - Do not have chloroplasts - No membrane bound nucleus, have a nucleoid - Have circular DNA - Divid via binary fission List characteristics of Eukaryote - correct answers- All have cell wall made of chitin, cellulose, except for animals don't have cell walls - Have chloroplasts - Have a membrane bound nucleus - Have linear DNA - Divid via mitosis and meiosis Eukarya - correct answers- contain a distinct nucleus surrounded by a lipid membrane - Some are macroscopic, others are microscopic - Consists of fungi (yeasts and molds, protozoa, algae, and some helminths Archaea - correct answers- no membrane bound nucleus - unicellular and most are microscopic - typically found in extreme environments Bacteria - correct answers- no membrane bound nucleus - unicellular and most are microscopic - have gram (+) and gram (-) Fungi - correct answers- a eukaryote - derive nutrients from nonliving or decaying organic material - important for cycling the nutrients on Earth - mycorrhizal fungi: contained in 90% of plants - more tolerant to low pH than bacteria Molds - correct answers- a type of fungi - multicellular, filamentous fungi, composed of hyphae - reproduce asexually Aerial hyphae (molds) - correct answersoriginate from the vegetative hyphae, extend upwards, and support spores Vegetative hyphae (molds) - correct answersdigest and absorb nutrients Rhizoidal hyphae (molds) - correct answershelp anchor the mold to the substratum Yeasts - correct answers- non-filamentous, unicellular fungi that are five to ten times larger than bacteria - reproduce by budding - Classified by metabolic activities Sabouraud's Dextrose Agar (SDA) - correct answers- used for growing yeasts and molds (fungi) - high sugar concentration and slightly acidic (pH = 5.6) so bacteria can't grow Lactophenol Cotton Blue Stain (LPCB stain) - correct answers- allows examination of fungi - lactic acid and phenol help to kill and preserve the organism - cotton blue stains the chitin in cell wall Protozoa - correct answers- Eukaryotic - unicellular and lack a cell wall - require water to survive - capable of motility Algae - correct answers- simple eukaryotes - obtain energy via photosynthesis - most are aquatic - Primary producers of O2 Helminths - correct answers- large macroscopic eukaryotes - long lived organisms which multiple life cycles - consist of flatworms and roundworms - Need a host to obtain energy Defined Media - correct answersthe exact composition and quantity of each nutrient is known Complex media - correct answerscontain same elements as defined media but the amounts of each particular nutrient may vary Agar - correct answers- growing media for microbes - can be liquid, solid, or semisolid Agar slant - correct answers- the agar is allowed to dry within a test tube on a slant Agar deep - correct answers- the agar dries in a test tube when its standing upright Agar plate - correct answers- the agar is in liquid form, then pour into a petri dish and dried creating a solid growing surface Agar pour - correct answers- liquid medium is pour into a petri plate for later use Autoclave - correct answers- a sterilization technique for media and lab instruments - uses "moist heat" heated to 121 celsius killing microbes dry heat sterilization - correct answers- used to sterilize glassware - put things in an oven at high heat to kill microbes - 170 celsius for 90 seconds Filtration - correct answers- used for media additives that cannot withstand heat sterilization - the filter traps microbes and lets the liquid pass UV radiation - correct answers- used to sterilize air in hospitals or surfaces contamination - correct answers- The introduction of dangerous chemicals, disease, or infectious materials. - microbes are everywhere so things can be contaminated easily aseptic technique - correct answers- a process to preserve the purity of objects - Requires a bunsen burner - a loop is to be flamed before and after dipping it in a solution - a test tube should be flamed before and after taking a sample - loop needs to cool before collecting sample Pure culture - correct answersis simply a culture with one type of organism present How to prepare a smear plate - correct answers- always use aseptic technique - a loop-ful of liquid bacteria culture can be spread over the surface of a glass slide and air-dired - one loop-ful is ideal amount Simple Stain - correct answers- consist of using a single die - used to show info about cell shape, size, and arrangement of bacterial cells - color will be color of dye Differential stain - correct answers- composed of two or more dyes - used to differentiate between organisms cellular components - gram stain Gram-positive bacteria - correct answers- Thicker layer of peptidoglycan cell wall - has teichoic acids that extend through cell wall - lipoteichoic acids help anchor peptidoglycan to cytoplasmic membrane - Turn violet during gram stain, cell walls shrink pores in peptidoglycan Gram-negative bacteria - correct answers- Thinner layer of peptidoglycan cell wall - have an outer membrane composed of lipopolysaccharides - turn red during gram stain, violet is washed out when 95% ethanol is added because of less peptidoglycan for the violet to soak in to Gram stain - correct answers1) heat-fixed smear is flooded with crystal violet 2) addition of mordant (gram's iodine) that creates a crystal violet-iodine complex 3) cells are washed with de-colorizer (95% ethanol) 4) finally, a counterstain of safranin is used Physical requirements for bacteria - correct answers- water activity - proper temperature - proper pH - oxygen concentration Chemical requirements for bacteria - correct answers- Essential elements (needed): carbon, oxygen, nitrogen, hydrogen, etc. - Trace elements (still needed): zinc, cobalt, copper, etc. Chemoheterotrophs - correct answersAn organism that must consume organic molecules for both energy and carbon. Chemoautotrophs - correct answersObtain energy from organic sources and obtain carbon from carbon dioxide Photoheterotrophs - correct answersEnergy from sunlight, carbon from organic compounds Photoautotrophs - correct answersobtain energy from sunlight and carbon from carbon dioxide Lithoautotrophs - correct answersobtain energy from inorganic compounds and carbon from carbon dioxide Lithoheterotrophs - correct answersobtain energy from utilizing inorganic compounds and carbon from organic chemicals Selective Media - correct answersgrow only one particular group of microorganisms that is present within a mixed population Differential media - correct answersdifferentiate between organisms growing in a culture selective and differential media - correct answersselect for specific organisms, and then differentiate between the organisms capable of growing under those selective conditions complex all-purpose growth medium - correct answersgrow all the organisms in a mixed population of microbes Streak plate - correct answers- a method to isolate microbial colonies - First the petri plate is divided into 4 quadrants - Then the loop is flamed to acquire the sample - The sample is then spread into a few line in the first quadrant - The loop is flamed again, spreads the plated organism into quadrant two. - process is repeated until all 4 quadrants have been streaked Tryptic soy agar (TSA) - correct answers- complex medium used for the isolation of most microbes - inhibits fungi growth because to high of pH Columbia CNA agar with 5% sheep blood - correct answers- is a selective and differential media - used to isolate and differentiate gram (+) bacteria - can differentiate between different hemolysis patterns