Download MICROBIOLOGY MIDTERM 1 EXAM WITH CORRECT AND VERIFIED ANSWERS 2025 - UNIVERSITY OF CALIFOR and more Exams Nursing in PDF only on Docsity!
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
DAVIS)
Pathogenic - correct answers Cause infection/disease, food spoilage Eukaryotic vs. Prokaryotic - correct answers Prokaryotic cells: Lack membrane-bound organelles Lack a nuclear membrane Generally smaller in size compared to eukaryotes Peptidoglycan - correct answers Makes up bacterial cell wall Bacillus - correct answers rod-shaped Coccus - correct answers Spherical Spiral - correct answers corkscrew-shaped Archaea - correct answers Single-celled organisms, have a cell wall (no peptidoglycan)
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
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Structure and function are very similar to bacteria Non-pathogenic to humans Nutrition: environmental nutrients, photosynthesis/carbon fixation Methanogens - correct answers Archaea produce methane as a waste product Extreme halophiles - correct answers Archaea live in extremely salty environments Extreme thermophiles - correct answers Archaea live in extremely hot environments Protozoa - correct answers Eukaryotic Unicellular organisms, no cell wall Exist in a variety of shapes and sizes Move using pseudopods (extensions of the cytoplasm), flagella, or cilia Can live as freely as self-sufficient organisms, but also as parasites
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
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Zacharias Jansen - correct answers Discovered/invented compound light microscope Robert Hooke - correct answers first person to describe microorganisms Cell Theory - correct answers all living things are composed of cells Leeuwenhoek - correct answers 1600s; magnifying lens and microscope; looked at bacteria, red blood cells, and yeast theory of spontaneous generation - correct answers states that life can spontaneously emerge from nonlife Louis Pasteur - correct answers showed that microorganisms are present in air and can contaminate sterile solutions, but that the air itself does not generate those microbes fermentation reactions - correct answers Yeasts can convert sugars to alcohol to make wine and beer in the absence of oxygen
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
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When exposed to air, alcohol is converted to acetic acid (vinegar) by bacteria, making it sour pasteurization - correct answers partial sterilization of foods at a temperature that destroys harmful microorganisms without major changes in the chemistry of the food germ theory of disease - correct answers idea that infectious diseases are caused by microorganisms, or germs Semmelweis - correct answers disinfecting hands reduced disease transfer Lister - correct answers started applying phenol to surgical wounds to kill bacteria it worked so well that other surgeons adopted it Heat-sterilized instruments Koch's Postulates - correct answers 1) Pathogen must be present in all disease cases
- Isolate pathogen, cultivate in pure culture
- Inoculate into susceptible animal, initiate disease symptoms
- Re-isolate pathogen, confirm it's the same pathogen
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
DAVIS)
Differential Stains - correct answers Used to differentiate organisms into two different categories Don't stain all cells the same colour eg. Gram stain Gram positive - correct answers cells are purple d/t crystal violet Gram negative - correct answers cells are pink because of the counterstain (safranin) Theory of RNA World - correct answers the idea of self-replicating RNAs carrying out all of the processes necessary for their replication Montmorillonite clay - correct answers Lipid vesicles spontaneously form, very similar to cells Can also cause spontaneous formation of RNA oligonucleotides stromatolites - correct answers layered rocks that form when certain prokaryotes bind thin films of sediment together
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
DAVIS)
cyanobacteria - correct answers Photosynthetic, oxygen-producing bacteria (formerly known as blue-green algae).
- greatly altered the content of Earth's atmosphere
- Formation of the ozone layer
- Availability of oxygen as an electron acceptor in metabolic processes Endosymbiosis - correct answers Process through which early prokaryotic cells are thought to have engulfed other, smaller cells and eventually incorporated them as organelles; these cells evolved into modern-day eukaryotes. hypertonic - correct answers A cell with a higher concentration of water inside of the cell than out. It pushed water out and shrivels up Hypotonic - correct answers A solution where the concentration of dissolved material inside the cell is higher than outside. Causes the cell to swell. osmotolerant microbes - correct answers able to adapt/survive in MILDLY hypertonic environments Acidophiles - correct answers grow best in pH 0 to 5.
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
DAVIS)
Proteobacteria - correct answers Sulfur-oxidizing bacteria Methanotrophs and Methylotrophs, - correct answers use methane (CH4) and other one-carbon compounds as electron donors for metabolic processes Pseudomonads - correct answers each species can use a variety of carbon sources for metabolic processes (between 20-100 depending) Vibrio sp. and Photobacterium sp. - correct answers curved rods, mostly aquatic and found in either freshwater or marine habitats, and some are bioluminescent luciferase - correct answers enzyme involved in bioluminescence, produced by Photobacterium magnetosomes - correct answers Contain crystals of magnetite or greigite, allowing cells to respond to magnetic fields. Sheathed Proteobacteria - correct answers filamentous bacteria special life cycle, involving the release of swarmer cells from the sheath to facilitate their dispersal
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
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GC - correct answers Guanine-Cytosine content Non-sporulating, low GC - correct answers Staphylococcus sp. Micrococcus sp. Sarcina sp. Streptococcus sp. Lactobacilli sp. Listeria sp. Acetic acid bacteria - correct answers perform incomplete oxidation of alcohols and sugars, leading to the production of organic acids.
- tolerant to acidic conditions, used in industrial processing of foods, and also to create cellulose this helps them to remain at the surface of liquids near oxygen Acetobacter sp. - correct answers uses ethanol as a carbon source to form acetic acid Bdellovibrio sp. - correct answers these bacteria prey on other bacterial species for nutrients
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
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Lactobacilli - correct answers fermentative, acid-resistant bacteria found commonly in dairy products Listeria sp. - correct answers fermentative coccobacilli Endospore-forming, low GC - correct answers Bacillus sp. Clostridium sp. Bacillus sp. - correct answers produce antibiotics are toxic to many insect larvae some are extremely pathogenic to humans Clostridium sp. - correct answers responsible for several human diseases including tetanus, botulism, and gas gangrene Actinobacteria, High GC - correct answers Corynebacteria sp. Mycobacterium sp. Streptomyces sp.
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Acid-fast - correct answers Acid-fast retain the red stain, Non-acid-fast organisms do not, and appear blue Corynebacteria sp. - correct answers v-shaped caused by a snapping movement occuring after cell division Mycobacterium sp. - correct answers contain special lipids called mycolic acids that cause them to stain acid-fast Streptomyces sp. - correct answers extremely diverse and are known for being very filamentous laments form a mycelium, which is characteristic of many fungi Cyanobacteria Definition - correct answers photosynthetic: they have one chlorophyll form (chlorophyll a)
- Contain phycobilins phycobilins - correct answers a photosynthetic pigment
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Elementary bodies - correct answers found in Chlamydia sp. small, dense cells that are resistant to the environment Used for dispersal of the pathogen Reticulate bodies - correct answers Found in Chlamydia sp. divides readily and is the vegetative form once inside the host cell Planctomyces sp. - correct answers ONLY PROKARYOTES SHOWN TO HAVE COMPARTMENTALIZATION Planctomyces - correct answers considered to be stalked bacteria --> the stalks are made of protein Verrucomicrobia - correct answers Named for their "warty" appearance, members of this species exhibit prostheca prostheca - correct answers cytoplasmic appendage of Verrucomicrobia sp Flavobacteria genus - correct answers Bacteroides sp. Flavobacterium sp.
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
DAVIS)
Flavobacteria - correct answers extremely variable and can be found in many different habitats, and some members are psycrophilic or psychrotolerant psycrophilic - correct answers bacteria that grow in cooler temperatures psychrotolerant - correct answers can grow at cold temperatures Bacteroides sp. - correct answers present in human feces (10^10 cells per gram), and are known for synthesizing sphingolipids Cytophaga Group - correct answers Rods with pointed ends
- Move by gliding
- Mostly digest polysaccharides saprophytes - correct answers Exist on waste products and decaying organisms Green Sulfur Bacteria - correct answers nonmotile Phototrophic,
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Deinococcus radiodurans - correct answers Extremely resistant to radiation (can withstand 10x more radiation than a human)
- DNA is extremely stable
- Resistant to other mutagens *DNA is assembled into a toroidal, ring-like structure Green Nonsulfur Bacteria - correct answers Members of this phylum are thermophilic and alkalophiles Branching Hyperthermophilic Bacteria - correct answers extremely resistant to heat; they are often found around hydrothermal vents and other exceptionally hot places Thermotoga sp. - correct answers Branching Hyperthermophilic Bacteria
- Have a sheath that resembles a "toga" Aquifex sp. - correct answers Branching Hyperthermophilic Bacteria
- Most thermophilic of all known bacteria,
- Can survive up to temperatures of 95 °C
CORRECT AND VERIFIED ANSWERS 2025 -
UNIVERSITY OF CALIFORNIA, DAVIS (UC
DAVIS)
Euryarchaeota - correct answers Some members of this phylum extremely halophilic Presence of salt is required for them to survive bacteriorhodopsin - correct answers Pigmented protein found in the plasma membrane of a salt-loving euryarchaeote
- Pumps protons out of the cell in response to light. Thermoplasmatales - correct answers thermophilic and some are extremely acidophilic prokaryotes Ferroplasma sp. - correct answers Thermoplasmatale not thermophilic, but are extreme acidophiles They perform a reaction to oxidize Fe2+ to Fe3+, which generates acid Picrophilus sp. - correct answers Thermoplasmatale
- Extreme acidophile, growing at a pH of 0.6-0. This organism requires a low pH; its membrane becomes leaky around pH 4 Thermococcales - correct answers hyperthermophilic
