VBS 2032 Exam 1 Questions and Answers Graded A+

VBS 2032 Exam 1 Questions and Answers Graded A+ What does the term "ubiquity" mean? - answerFound everywhere on the planet What are some surprising places microbes are found? - answerFound in hot springs and nutrient poor environments beneath glaciers How can microbes travel - answerAir, skin to skin We do not yet know the extent of microbial diversity. Why not? - answerStill developing new techniques for sequencing the DNA and RNA from environmental samples What are three ways in which microbial activity is essential for life on this planet? - answerNitrogen fixation, recycling, and O2 production Where are several places microbial biofilms can be found in daily life? - answerOn teeth, on toilet bowls, in kitchen drains What are two ways microbes have changed that impact healthcare? - answerMicrobes have become antibiotic and disinfectant resistant, they can help boost your immune system Most microbes are not harmful. What are some reasons for this? - answerThey would have to be able to avoid our immune system, grow at body temperature, and extract nutrients from tissues. This is difficult to do. Your friend recently ate a salad containing a brand of spinach that was recalled for contamination with E. coli. Can you explain to her the factors that will influence whether or not she becomes ill? - answerNumber of microbes- how many she consumed Virulence of microbe- how well the microbes can evade her immune system Host immunity- is she immune of immunocompromised? What are some ways that the Chain of Infection can be broken? - answerIsolate and treat patient, wash hands and disinfect surfaces, vaccinate Describe three ways our changing relationship with wildlife affects the emergence of new infectious diseases. - answerHabitat destruction, the dilution effect, and the wildlife trade What can we do to avoid the next pandemic? - answerFind out what viruses there are in wildlife and work with the communities that are on the front line An increase in the ___________will decrease the likelihood of infection. - answerHost immunity Nitrogen fixation is an essential process carried out by: - answerAlgae and bacteria What two scientists are credited with discovering microorganisms? - answerRobert Hooke and Antoni van Leewenhoek Is a virus considered a microorganism? Why or why not? - answerNo because they are acellular and are not alive What are some basic differences between prokaryotic and eukaryotic cells? - answerEukaryotes have a nucleus and membrane bound organelles whereas a prokaryote does not What are the relative sizes of a human cell, a protein, a virus and most bacteria? - answerHuman cell: 10-100 microm, protein: 10 nm, virus: 100 nm, bacteria 1-10 microm How are microorganisms named? - answerGenus (name or shape) first then species Why did some scientists have difficulty achieving the same result as Pasteur with the swan-necked flask? - answerSince Pasteur used a yeast extract and sugar broth there were no heat resistant microbes in his broth What two scientists helped explain the conflicting data? - answerTyndall and Cohn Can you explain how the swan-necked flask experiment helped disprove the idea of spontaneous generation? - answerWhen the broth was boiled the microbes got trapped in the curve of the neck, the broth did not become cloudy until the flask was tipped and the microbes were reintroduced to the broth How could the potato salad have been prepared safely? (Why did people become ill?). - answerIf the potato salad was used with canned potatoes using the pressure cooker method the high temperature would have killed the endospores. Why was there only one fatality? - answerThere are many factors that contribute to whether or not someone will die from an illness The scientific name of an organism includes its - answerGenus and species The idea of spontaneous generation postulated that: - answerliving organisms could spontaneously arise from non-living material What is a virulence factor? - answerTraits of a microbe that promote pathogenicity What parts of the cell can act as virulence factors? - answer(different agents used by the pathogen to sneak a disease into our system) · Flagella: composed of the protein flagellin, function in motility · Pili (Fimbriae): DNA exchange, adherence, motility · Glycocalyx: slime layers and capsules used for attachment, protection from desiccation, host evasion · Endospores: resistant to heat, UV, desiccation, toxic chemicals thus, hard to kill, standard disinfectant cannot kill (C. diff) · Biofilms What is a ribosome composed of? What is the function of a ribosome? - answer· small and large subunits composed of rRNA and proteins · synthesizes protein What are the basic components of a cell membrane? What are some functions that membrane proteins serve? - answerCell membranes are in all organisms, composed of phospholipids and are semi-permeable. Used for structure and protection How do bacteria move? How might this increase a pathogen's ability to cause disease? - answerBacteria can move by twitching, gliding, and axial filaments. They can move with flagella and pili. They use the virulence factors to move. What is "C. diff"? Why is it difficult to control in a hospital setting? - answerC. diff is Clostridium difficile which causes colitis. It is hard to control in a hospital setting because it contains endospores which are resistant to heat, UV desiccation and toxic chemicals. Could penicillin be used to treat a patient with pneumonia caused by Mycoplasma pneumoniae? Why or why not? - answerNo, because Mycoplasma does not contain a cell wall which is what penicillin works against. A spherical bacterium would be called a - answercoccus A research laboratory is investigating factors that would inhibit the growth of Archaea. One question they have is if adding the antibiotic penicillin would be effective in controlling growth. What do you think the outcome would be if they tried this? - answerThe penicillin wouldn't affect the Archaea because it prevents crosslinking of peptidoglycan-Archaea don't have this compound in their cell walls. What properties of bacterial cell walls allow for discrimination by the Gram stain? The Acid-fast stain? What group of bacteria is considered "acid-fast"? - answerGram positive have a thick peptidoglycan wall. Gram negative have an extra cell outer membrane. The Acid-fast stain works on bacteria have have a waxy coating that prevents entry of the gram stain. Mycobacteria are considered "acid-fast" What kinds of bacteria lack cell walls? What is an example of an obligate intracellular bacterium? (What does obligate intracellular mean?) - answerMycoplasma lack cell walls. Chlamydia is an obligate intracellular bacterium. It means that they have to live inside your cells. What are the basic differences between Gram-positive and Gram-negative bacteria? What is a porin? What is the medical significance of LPS? - answerGram Positive: have a thick peptidoglycan layer, stains, purpleGram Negative: have an extra membrane, outer membrane, pink, LPS LPS is immunogenic- immune system thinks the molecule is foreign Which group of bacteria is likely to be most resistant to disinfectants and antibiotics? Why? - answerGram negative because they have a largely impermeable cell wall According to the Endosymbiotic Theory, what is the origin of mitochondria? Of chloroplasts? (What takes place in the chloroplast?) - answerMitochondria- double membrane, DNA sequence of chromosomes is similar to Rickettsia, similar ribosomes (70S) Chloroplast- double membrane, DNA sequence similar of chromosomes is similar to cyanobacteria (photosynthesis takes place) How are bacterial and eukaryotic ribosomes different? (What is the function of a ribosome?) - answerAll ribosomes synthesis proteins, Bacterial: 70S, Eukaryotic: 80S What is a phylogenetic tree? - answerA phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the evolutionary relationships among various biological species or other entities—their phylogeny —based upon similarities and differences in their physical or genetic characteristics Which organelles came first: mitochondria or chloroplasts? - answerMitochondria came first How are autotrophs and heterotrophs different? - answerAutotrophs make their own food whereas heterotrophs don't Why don't most people get fungal lung infections? - answerFungus almost never enter the body and grow What are two forms of pathogenic protozoa? Which one persists in the environment? - answerTrophozoite: form that infects the body (do not survive in the environment), Cyst: characterized by a thickened cell wall, very stable in the environment Algae and Protozoa share the following characteristics - answerBoth have cell walls A yeast infection should be treated with a ________ drug: - answerantifungal What is the difference between an enveloped and non-enveloped virus? What is the envelope composed of and where do viruses obtain an envelope? - answerNon-enveloped viruses contain a DNA/RNA genome in a protein capsid (capsids contain a special protein called a spike that adhere to a host and therefore determine what host the virus can attach to), Enveloped virus contains an extra layer (a lipid bilayer) that is NOT considered a CELLULAR membrane. Envelopes are usually derived from portions of the host cell membrane. The envelope is composed of phospholipids and proteins. What is the difference between lytic and temperate phages? - answerPhages that replicate only via the lytic cycle are known as lytic phages while phages that replicate using both lytic and lysogenic cycles are known as temperate phages. In the lysogenic cycle, the phage DNA first integrates into the bacterial chromosome to produce the prophage. When a bacterium is in a state of lysogenic conversion, why does it express a different protein(s)---often a toxin? What does this mean for the pathogenicity of the bacterium? - answerThe phages infecting these bacteria carry the toxin genes in their genome and enhance the virulence of the host when the toxin genes are expressed. It increases the pathogenicity of the bacterium. What is an example of a human disease caused by reactivation of a latent virus? - answerBotulism (Clostridium botulinum), scarlet fever (streptococcus pyogenes), hemolytic uremic syndrome (E. coli). How do viruses attach to cells? - answerThe viruses attach to cells using spikes. Why are viruses usually specific for a single cell type and/or single host species? - answerViruses are more specific to single cell type or host species because they have a specific attachment site on that cell to attach to. Why are there relatively few antiviral drugs (as opposed to antibacterial drugs)? - answerThere are relatively few antiviral drugs because in order for them to work they have to inhibit host cell synthesis and development of the host cell. The host cell's functions would have to be destroyed in order for the virus to be destroyed. What is the difference between an acute, chronic and latent viral infection? Which one is most likely to spread when the host is asymptomatic? - answerAcute -> comes and then goes, chromic -> comes but acute symptoms last forever, latent -> always has it, could be asymptomatic. Latent is most likely to spread when the host is asymptomatic. Is there a cure for prion disease? - answerNo Can viroids infect humans? Where do viroids cause significant disease? - answerViroids can not infect humans. Viroids cause significant disease in plants. What is the human "phageome"? How is this distinct from the virome? - answerPhageome -> collection of all phages in and on the human body, Virome -> collection of all viruses in and on the human body Describe the structure of the SARS-CoV-2 virus. In basic terms, how does it replicate? - answerStructurally, SARS-CoV-2 has four main structural proteins including spike (S) glycoprotein, small envelope (E) glycoprotein, membrane (M) glycoprotein, and nucleocapsid (N) protein, and also several accessory proteins. The replication is a complex process involving the action of several viral and host proteins in order to perform RNA polymerization, proofreading and final capping. Viroids are known to infect: - answerPlants An antiviral drug that binds to a viral spike protein would directly prevent: - answerattachment What does the term "generation time" mean? How can the total number of cells in a population be calculated if the generation time is known? (What is the formula and can you use it?) - answerGeneration time means the time it takes for the amount of bacteria population to double.N02^n=Nt What are the phases of the growth curve? What is happening during each phase? How might bacterial growth in pure culture be different than growth in a natural setting? - answerLag, log, stationary, death, Lag-> bacteria not yet multiplying quicklyLog-> nutrients are growing/multiplying exponentially, waste starts to build up and nutrients run lowStationary-> cells dying=cells being created,Seath-> more cells dying than being created, can last for a long time What does the term "planktonic" mean? - answerIn suspension or not in biofilm What is EPS? What does it do? - answerExtra polymeric substance- sticky substance, polysaccharides, DNA, various polymers, encased in EPS, can divide within What is an example of a way in which microbes can cooperate in a biofilm? - answerOne cell can be resistant to an antibiotic and therefore can resist the antibiotic and save all of the other microbes in the biofilm. What is a way in which microbes can compete in a biofilm? - answerThey are competing for space. Why are microbes generally more resistant to antibiotics and disinfectants when growing in a biofilm? - answerHarder for antibiotics to get into the biofilm. Even if antibiotics did get in they would not be very susceptible because they are not growing/dividing they are persisting. One cell can be resistant to an antibiotic and therefore can resist the antibiotic and save all of the other microbes in the biofilm. Why would an infection involving a biofilm be difficult to treat? Why might the microorganisms be difficult to identify? - answerAn infection with biofilm would be hard to treat because of their resistance to antibiotics. Difficult to identify which organism is causing the infection because there are many growing. What are two enzymes that obligate aerobes and facultative anaerobes make that protect the cells from reaction oxygen species (ROS)? - answerCatalase-> breaks down H2O2 and produces Oxygen, reason that H2O2 produces bubblingSuperoxide dismutase-> Gets rid of superoxide What is the difference between an acidophile and a neutrophile? Which one would grow in a jar of pickles? - answerNeutrophile-> best in pH of 5-8Acidophile-> best in acidic pHAcidophiles would grow best in jar of pickles Why is salt a good preservative? - answerMakes water move out of cells and they shrivel and can't reproduce/live What is a chemoorganoheterotroph? A photoautotroph? - answerchemoorganoheterotroph-> get energy from organic compounds and carbon from organic compoundsphotoautotroph-> energy from sunlight and carbon from CO2 Why does the research described in "An Irresistible Newcomer" represent a breakthrough discovery? - answerThe antibiotic is not resistant. They grew "uncultivatible" soil bacteria using an overlay of soil. Not next to other bacterium, but the necessary bacteria diffuse in. Add MRSA on top, little clearings were the MRSA couldn't grow and under that was the new antibiotic that was growing. The antibiotic helped treat MRSA. Couldn't generate antibiotic resistance to this drug very easily A bacterial species was isolated from the middle of a compost pile where the temperature was 55-65oC. The group that best describes this microorganism would be: - answerThermophile Scientists were unable to culture bacterium X from a soil sample even though DNA sequence data indicated that the bacterium was present. Why? - answerA, B and C could be correct. Metabolism - answerthe sum of all the chemical reactions in the cell Photoautotroph - answerenergy source and carbon source are sunlight Chemoorganoheterotroph - answerenergy source and carbon source are organic matter Reducing power - answerreduced electron carrier What is the energy currency of the cell? What general set of reactions produce it? What type of reactions use it? - answerATP is the energy currency. Aerobic respiration, anaerobic respiration, and fermentation produce it. Active transport, secretion, endocytosis, synthesis and replication of DNA, and movement use ATP. What are precursor metabolites used for? - answerThey are either oxidized to generate ATP of the can be used to synthesize macromolecular subunits. What are enzymes most commonly composed of? - answerProteins or amino acids Why are enzymes necessary? - answerThey allow chemical reactions in the body to happen by lowering the activation energy Where does the substrate bind on an enzyme? How does the enzyme catalyze the chemical reaction? - answerBinds to the active site and lowers the activation energy. What environmental factors influence enzyme activity? - answerTemperature, pH, and concentration What is reducing power? What are two molecules used as reducing power in metabolic pathways? - answerThe strength of a chemical's ability to reduce another substance. NADH, FADH2 What is the function of each of the pathways below? What is the input and yield of each? - answerGlycolysis- 2 ATP + 2 NAD+ à 4 ATP + 2 pyruvate, + 2 NADH Transition Step- 2 pyruvate à 2 Acetyl CoA + 2 CO2 + 2 NADH + 2 H+ TCA cycle- 2 Acetyl CoA à 4 CO2 + 6 NADH + 6 H+ + 2 FASH2 + 2 ATP + 2 CoA Cellular respiration- C6H12O6 + O2 à H2O + CO2 Can cellular respiration be anaerobic? What type of molecule would be the final electron acceptor? - answerYes, NO3 What is substrate-level phosphorylation? How is it different from oxidative phosphorylation? - answerSubstrate level phosphorylation directly phosphorylates ADP to ATP by using the energy from a coupled reaction. While oxidative phosphorylation involves two coupled reactions that are considered to simultaneously occur. What is the electron acceptor in fermentation? What are some byproducts? - answerPyruvate is the electron acceptor, some by products are lactic acid and ethanol What fermentation byproduct can accumulate in muscles during intense anaerobic exercise? - answerLactic acid What ATP generating options would an obligate aerobe have? A facultative anaerobe? An obligate fermenter? An obligate anaerobe? - answerObligate aerobe- aerobic and anaerobic respiration and fermentation Facultative anaerobe- aerobic and anaerobic respiration and fermentation Obligate fermenter- fermentation Obligate anaerobe- anaerobic respiration and fermentation How can bacteria use carbon/energy sources other than glucose as starting molecules? - answerCan use polysaccharides, disaccharides, lipids, or proteins Why should you re-cork you wine after you open it? - answerSo the ethanol does not become acetic acid How did scientists make the link between bacterial metabolism and TMAO accumulation? - answerBy studying people who eat steak, take antibiotics, and develop heart disease What does the term "fastidious" mean in microbiology? - answerThe more restrictive term fastidious microorganism is used in microbiology to describe microorganisms that will grow only if special nutrients are present in their culture medium. From a microbiome point of view, why might eating trehalose be bad for you? How did the RT078 strain change so that cells could use trehalose? How does this strain become more virulent when trehalose is present? - answerTrehalose is being linked with the rise of two strains of the bacterium Clostridium difficile, capable of causing diarrhea, colitis, organ failure, and even death. It had extra genes that encoded a transporter to get trehalose into the cytoplasm of the cell. It uses trehalose for energy. We don't know where if got these genes from. In terms of the human microbiome and metabolism, why is eating a fiber-rich diet good for you? - answerIt gives us more and more diverse microbes in out gut. How are pickles made? What factors promote the growth of lactic acid bacteria? What inhibits the growth of spoilage bacteria? Where do the "good" lactic acid bacteria come from? - answerPickles are made by submerging cucumbers in salty water. The lack of oxygen and right temperature and presence of salt promote the growth of lactic acid bacteria. The salt inhibits the growth of spoilage bacteria. The "good" lactic acid bacteria come from the cucumbers. In eukaryotic cells, energy is generated in this organelle: - answerMitochondria At the completion of the electron transport system, electrons originally present in glucose have been transferred to: - answerOxygen In the absence of oxygen, some bacteria can obtain some energy from glycolysis followed by: - answeranaerobic repiration The function of NADH and FADH2 in electron transport is to: - answerdonate electrons Antiseptic - answerused on skin or body tissues, they reduce the number of microbes Disinfectant - answermost or all pathogens are eliminated Sterilant - answercompletely removes or destroys all microbes, with the exception of prions Sterilization - answerto completely remove or destroy all microbes, with the exception of prions Pasteurization - answerNOT sterile; reduces the level of pathogens and spoilage bacteria Disinfection - answerto eliminate most or all pathogens Bacteriostatic - answerbacterial growth is inhibited, but cells are not killed Bactericidal - answerkills bacteria Preservation - answerinhibition of microbial growth that delay spoilage Where might copper be used in a hospital setting? - answerDoor handles How and when are endospores formed? What two bacterial genera produce endospores? - answerEndospore formation is usually triggered by a lack of nutrients, and usually occurs in gram-positive bacteria. In endospore formation, the bacterium divides within its cell wall, and one side then engulfs the other. Endospores enable bacteria to lie dormant for extended periods, even centuries. The geneses of Bacillus and Clostridium produce endospores. What type of microbes are most resistant to disinfection? What types are most sensitive? - answerPrions are most resistant to disinfection. Enveloped viruses are the most sensitive. If heating a bacterium at 55 c for 10 minutes kills 90% of the cells, what percent would be killed in 20 min? - answer99% How is milk typically Pasteurized? How does the fat in ice cream affect the conditions for Pasteurization of ice cream? - answerIn most milk processing plants, chilled raw milk is heated by passing it between heated stainless steel plates until it reaches 161° F. It's then held at that temperature for at least 15 seconds before it's quickly cooled back to its original temperature of 39° F. Ice cream is rich in fats, so it is pasteurized at 82 degrees C for about 20 sec Compare and contrast the different types of heat treatments. Which one(s) result in sterilization? - answerDry heat, boiling, pressurized steam, Pasteurization, incineration Pressurized steam, dry heat, and incineration result in sterilization Why does Pasteurized milk eventually spoil in your refrigerator? - answerPasteurization is not sterile so some microbes still exist in the milk. How could you sterilize a hospital mattress? - answerHydrogen peroxide spray that can penetrate through layers and crevices in a mattress Does food need to be sterile? Who is most at rick for food-borne illness? - answerNo, those with compromised immune systems are most at risk (elderly) What are the limitations of UV radiation for use in sterilization? - answerIt penetrates poorly, it cannot be used to destroy microbes in solid substances or turbid liquids, and it must be used carefully because UV rays can damage skin and eyes and promote the development of skin cancers How does UV-C light kill microbes? - answerUV rays are able to penetrate walls of viruses and bacteria If you planned to invest money in a biomedical equipment firm, would you choose Bioquell or Xenex? Which machine is more effective in your opinion? - answerBioquell, UV treatment has too many limitations Which is more sensitive to chemical treatment, enveloped or non-enveloped viruses? Why? What are Mycobacteria more resistant than Gram + bacteria? - answerNon-enveloped viruses are more resistant to bacteria than enveloped. Mycobacteria are more resistant than gram + because they have a thick, waxy, hydrophobic cell envelope and the presence of drug degrading and modifying enzymes Protozoal cysts can be resistant to chlorine. Why is this significant? - answerChlorine is used in many chemical disinfectants How do salt and sugar protect foods from microbial spoilage? - answerSugar or salt pulls water out of microbes so they are unable to grow A suffix used to describe a killing action would be - answer-icidal The process of killing or removing all of the microorganisms in or on a material is termed - answersterilization A common environmental organism that may even grow in certain chemical disinfectants is - answerPseudomonas aeruginosa What is a genome? - answerThe microbial genome contains the genetic information How does the Central Dogma state how information transmitted? What is a viral exception to this? - answerReplication, transcription, translation; retroviruses are exception What does semi-conservative replication mean? - answerHalf is from parent DNA, half is from daughter DNA How does the arrangement of DNA in eukaryotes differ from that in prokaryotes? - answerEukaryotes- multiple, linear chromosomes Prokaryotes- single, circular chromosome What are the differences between DNA and RNA? - answerDNA- A, T, C, G, deoxyribose, double stranded RNA- A, U, C, C, ribose, single stranded How is information transmitted in replication, transcription and translation? - answerReplication copies DNA; transcription uses DNA to make complementary RNAs; translation uses mRNAs to make proteins What enzymes are used in the above processes? - answerDNA primase, DNA polymerase, DNA helicase, DNA gyrase, DNA ligase Discuss the different types of RNA and the significance of each - answermRNA carries genetic codes from the DNA in the nucleus to ribosomes. tRNA helps decode a mRNA sequence into a protein rRNA associates with a set of proteins to form ribosomes What does it mean that the genetic code is degenerate (redundant)? - answerMore than codons can code for the same amino acid Which base is unique to DNA? to RNA? - answerDNA- T, RNA- U How many nucleotides are used to encode an amino acid? - answer3 What is a polycistronic message? Are they found in prokaryotes or eukaryotes? - answerA polycistronic message encodes several proteins and is found in prokaryotes What is an operator? What binds to this element? - answerThe function of the operator within genetics is to regulate the production of a certain portion of the DNA. Repressor proteins bind to the operator What is a promoter? What binds to this element? - answerPromoter is a sequence of DNA to which proteins bind that initiate transcription of a single RNA from the DNA downstream of it. What is the difference between an inducible system and a repressible system? - answerInducible is always "off" whereas a repressible is always "on" Under what conditions will the lac operon be expressed? Under what conditions will the lac operon be repressed? - answerIt's expressed only when lactose is present and glucose is absent. Its repressed when lactose isn't present What would happen to the transcription of the lac operon if the gene for the repressor protein was mutated (non-functional)? What would happen if the operator sequence was mutated (non-functional)? - answerIt would always be on, even when not needed. There would be no transcription. How does quorum sensing work? - answerBacterial cells release signaling molecules and sense the concentration of them to tell how many other bacterial cells there are What are some bacterial functions that are regulated by quorum sensing? Why might it be advantageous to produce antibiotics only when cell density is high? - answerBioluminescese, nitrogen fixation, and sporulation. There are more so it is ok if some get killed. What is the significance of quorum sensing in the health care field? - answerBiofilms are found on medical devices, change expression when cell density changes What are some targets for antimicrobial drugs discussed in this lecture? How are they selectively toxic? - answerDNA gyrase, RNA polymerase, 70s ribosomes; killing them would stop certain processes Transfer RNA is involved in: - answerProtein synthesis The role of mRNA is: - answerto encode instructions for synthesis of protein High level of expression of the lac operon occurs when: - answerglucose levels are low and lactose levels are high Quorum sensing systems are involved in: a. biofilm formation b. virulence gene production c. bioluminescence lation - answerAll of the above What are two main reasons that bacteria change so rapidly? - answerMost bacteria have short generation times and bacteria experience horizontal gene transfer What are the different kinds of mutations and what are the results of these mutations? - answer· Silent mutation o Genetic code is redundant o Has no effect · Missense mutation o Results in codon for different amino acid o Changed but still functional or partially functional · Nonsense mutation o Codes for stop codon o Unlikely to function properly What is the difference between vertical and horizontal transmission? - answerVertical gene transfer (parent to offspring) Horizontal gene transfer (between different bacteria) What are the three major ways bacteria exchange genetic information? Can you describe them? - answer§ Transformation · DNA from a dead bacterium is taken up by a live bacterium § Conjugation · DNA is transferred between two bacteria that are physically joined § Transduction · Phages moving DNA from one bacterium to another What is the significance of this bacterial genetic information exchange? - answerFor the bacteria? The bacteria get to change and can become resistant For you? more resistant bacteria, more virulent bacteria Describe Griffith's Streptococcuspneumoniae experiment and what it demonstrated. - answerThe experiment tested enveloped and heat treated enveloped bacteria on mice. the enveloped killed the mice but heat treated and nonenveloped didn't, but when those 2 were added together it caused the mice to die. it proved transformation because non enveloped cells picked up envelopes from heat treated bacteria What is a plasmid and where are they found? What kinds of genes do plasmids carry? - answerPlasmid is a circular DNA and are independent of chromosomes. usually encode non-essential info. Found in the cytoplasm What is the relationship between the host microbiota, plasmids and transient pathogens? - answerHost microbiota carrying certain plasmids, such as R plasmids, can potentially transfer them to transient pathogens Discuss two mechanisms bacteria use to repair damage from ultraviolet light. - answerdirect reversal of the damage by a photolyase (photoreactivation), removing of the damaged base by a DNA glycosylase (base excision repair) What is a transposon and what is its significance? - answerA transposable element (TE, transposon, or jumping gene) is a DNA sequence that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. What is the difference between a lysogenic and lytic phage? - answerThe lytic cycle involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell. The lysogenic cycle involves the incorporation of the viral genome into the host cell genome, infecting it from within. Which type of information exchange involves phage? - answerTransduction What are some bacterial defense mechanisms against phages? Can you describe them? - answerRestriction-modification systems- This prevents infection by effectively destroying the foreign DNA introduced by an infectious agent CRISPR- It allows researchers to easily alter DNA sequences and modify gene function. Does the species concept apply well to bacteria? Why or why not? - answerNo because they vary greatly and can change quickly Compare and contract the bacterial core genome and pangenome - answerCore genome is what all share. Pangenome includes everything. How is CRISPR used in biomedical research? - answerSystem can be employed to create exceptionally customizable genetic adjustments such as chromosomal alterations. It represents an expeditious and comprehensible model for the initiation and progression of various tumors, as well as for drug sensitivity and resistance predictions in cancer. How was CRISPR used in gene therapy for sickle cell anemia?. - answerOne approach consists of repairing the gene for hemoglobin S in order to cause the normal form to be produced. The second approach involves replacing hemoglobin S with hemoglobin F. The process in which genetic information is transferred to a bacteria via a phage is: - answerTranduction Light energy is always required to repair DNA damage caused by UV in bacteria. - answerFalse The genetic diversity of bacteria is generated by:(select all that apply) - answera. mutation b. transformation c. conjugation d. transduction e. transposition If an inverted repeat element on a transposon was mutated, what would happen? - answerThe transposon would not be able to move.