MIP 300 (Exam #1)question n answers graded A+ 2023/2024

MIP 300 (Exam #1) You are tasked with trying to create an antibiotic to treat a bacterium called Bacillus nonstudyus. You find a drug that inhibits tetrapeptide crosslinking, and you also find it can inhibit this bacterium from sporulating. Based on the fact that this drug inhibits tetrapeptide crosslink formation, what step in sporulation is most likely being inhibited by this drug? - correct answer Formation of the cortex You have isolated a cell that possesses the following: double-stranded DNA and a nuclear membrane composed of a phospholipid bilayer. From this information, into which domain of living organisms would you classify this cell? - correct answer Eukarya You see a microbe that lacks a Golgi apparatus. What domain could this microbe be a part of? - correct answer prokaryotes (bacteria), archaea, Euskara While being the world's greatest TA, Trey suddenly begins to feel ill. After seeing a physician he is prescribed antibiotics for a bacterial infection. Trey takes the antibiotics but his symptoms become much worse just hours after taking them. Why might this have happened to poor Trey, and what does this tell us about the bacterium making him ill? - correct answer The bacteria causing the infection are Gram-negative. When they were exposed to the antibiotics they were killed. However, the bacteria contained endotoxin, so when they died they released the toxin in mass amounts, leading to severe symptoms. Bob the bacterium is placed in a high oxygen environment and has a doubling time of 20 minutes. Then Bob is placed in an environment with no oxygen and is found to have a doubling time of 6 hours. How would you classify Bob? - correct answer Facultative anaerobe You isolate a bacterium that causes severe disease in cats. You find that the cat's macrophage cells are unable to effectively phagocytose this bacterium. Which of the following structures would you expect to find on this bacterium resulting in the decreased phagocytosis? - correct answer capsule You are a microbiologist. You isolate a bacterial strain in your lab that stains green and pink with an endospore stain. How many different kinds of carbohydrates and amino acids would you most likelyexpect to find in the cell wall of this strain? (first # = carbohydrates, second # =amino acids) - correct answer 2, 6 Which of the following organisms would you predict can cause septic (blood) infections in babies? - correct answer Mesophilic, neutrophile You have been hired to screen unpasteurized milk for Mycobacterium bovis, the bacterium that causes tuberculosis in cattle. What stain would you recommend to screen the milk and how will it appear if the milk is contaminated with M. bovis? - correct answer Acid fast stain: hot pink You isolate an organism with 30S and 50S ribosomal subunits. This organism could be: - correct answer Prokaryotic, archaebacteria, eukaryotic You isolate an antibiotic that has been shown to inhibit the direct binding between NAG and NAM in peptidoglycan. What type of organism would you expect this antibiotic to be effective against? - correct answer Gram-negative and Gram-positive bacteria If you have a bacterium with a thick 52 nm peptidoglycan layer, what color will the bacterium appear if properly Gram stained? What kind of microscope will you use to observe the bacterium? - correct answer Purple; bright field light microscope You are performing a Gram stain on a bacterium that CANNOT produce endospores. What color will the cells appear if you do every step correctly? - correct answer either pink or purple You isolate a spore-forming bacterium that produces an endospore in the subterminal position. You perform an endospore stain on your new bacteria and realize you forgot to use heat with the primary stain. What will you see under the microscope? (assume the organism is sporulating) - correct answer Pink sporangium cells with a clear endospore You isolate a novel virus that causes hemorrhagic fever. Which of the following could be true? - correct answer It could have a DNA genome surrounded by a protein shell, It could have an RNA genome surrounded by a protein shell When performing a chemoattractant assay, why does the zone around the bacterial colony get larger? - correct answer The more attractant utilized by the bacteria, the further the bacteria must move to find more attractant.