Lab exam practice
Item 2 Flagella arrangement Part A Observe the micrograph and draw conclusions about the pictured bacterium. http://session.masteringmicrobiology.com/problemAsset/1556479/1/Flagella_05.jpg Based on your observation of the bacterium in this micrograph, select ALL appropriate statements. The indicated bacterium has a monotrichous flagella arrangement. The indicated bacterium has cilia. The indicated bacterium is motile. The indicated bacterium has a lophotrichous flagella arrangement. The indicated bacterium has a peritrichous flagella arrangement. The indicated bacterium has an amphitrichous flagella arrangement.
1) The indicated bacterium is motile. 2)The indicated bacterium has an amphitrichous flagella arrangement.
Two specimens, A and B, were inoculated into Urea broth. What can you conclude from your observations? http://session.masteringmicrobiology.com/problemAsset/1556524/2/Urea_test_07.jpg Based on your observation of the pictured Urease tests, select ALL appropriate statements. Bacterium A ferments lactose Bacterium A converted urea to ammonia Bacterium A increased the pH of the medium Bacterium B ferments lactose Bacterium B converted urea to ammonia Bacterium B decreased the pH of the medium Bacterium B does not produce urease
1)Bacterium A converted urea to ammonia 2)Bacterium A increased the pH of the medium 3)Bacterium B decreased the pH of the medium 4)Bacterium B does not produce urease
What can you conclude about the pictured bacteria? http://session.masteringmicrobiology.com/problemAsset/1556520/1/Endospores_07.jpg If a Gram stain was performed on this bacterium within 24 hrs of a fresh culture, it would most likely be Gram-positive. The pictured bacteria are bacilli The indicated structure is used for reproduction The indicated structure is a vacuole The indicated structure is a nucleus The pictured bacteria are cocci The indicated structure is an endospore
1)If a Gram stain was performed on this bacterium within 24 hrs of a fresh culture, it would most likely be Gram-positive. 2)The pictured bacteria are bacilli 3)The indicated structure is an endospore
Interpreting Simmons Citrate tests Two different bacterial samples, A and B, were inoculated onto Simmons Citrate agar. What conclusions can you make? http://session.masteringmicrobiology.com/problemAsset/1556532/1/Citrate_test_08.jpg Based on your observation of the pictured citrate media, select ALL appropriate conclusions. Specimen A cannot use sodium citrate as a carbon source Specimen A can use sodium citrate as a carbon source Specimen A raised the pH of the medium as a result of its metabolic processes Specimen B cannot use sodium citrate as a carbon source Specimen B can use sodium citrate as a carbon source Specimen B raised the pH of the medium as a result of its metabolic processes
1)Specimen A can use sodium citrate as a carbon source 2)Specimen A raised the pH of the medium as a result of its metabolic processes 3)Specimen B cannot use sodium citrate as a carbon source
Two different bacterial samples, A and B, were tested with an Oxidase dry slide. This is a picture of the test results. http://session.masteringmicrobiology.com/problemAsset/1556554/1/Oxidase_dry_slide_02.jpg Select ALL appropriate statements regarding the pictured Oxidase test results. Specimen A fermented cytochrome oxidase. Specimen A produces cytochrome oxidase. Specimen A does not produce cytochrome oxidase. Specimen B fermented cytochrome oxidase. Specimen B produces cytochrome oxidase. Specimen B does not produce cytochrome oxidase.
1)Specimen A does not produce cytochrome oxidase. 2)Specimen B produces cytochrome oxidase.
Two different bacterial samples, A and B, were inoculated into MR-VP (Methyl Red-Voges Proskauer) broth. The following image shows what the tubes looked like for the Methyl Red portion of the test. http://session.masteringmicrobiology.com/problemAsset/1556545/1/Methyl_red_test_01.jpg Select ALL appropriate statements regarding the pictured specimens that were subjected to the Methyl Red test. Specimen A fermented glucose and formed high levels of acid end-products Specimen A fermented glucose and formed low levels of acid end-products Specimen A can likely convert glucose to lactate, formate, or acetate Specimen B fermented glucose and formed high levels of acid end-products Specimen B is fermented glucose and formed low levels of acid end-products Specimen B can likely convert glucose to lactate, formate, or acetate
1)Specimen A fermented glucose and formed low levels of acid end-products 2)Specimen B fermented glucose and formed high levels of acid end-products 3)Specimen B can likely convert glucose to lactate, formate, or acetate
Two different bacterial samples, A and B, were inoculated onto Eosin Methylene Blue (EMB) agar. What can you conclude based on your observations? http://session.masteringmicrobiology.com/problemAsset/1556535/1/EMB_04.jpg Based on your observation of the pictured specimens that are growing on the EMB agar plate, select ALL appropriate conclusions. Specimen A is able to ferment lactose Specimen A is unable to ferment lactose Specimen A is likely to be Escherichia coli (E. coli) Specimen A is most likely Gram-negative Specimen B is most likely Gram-negative Specimen B is able to ferment lactose Specimen B is unable to ferment lactose Specimen B produces a base during the fermentation of lactose
1)Specimen A is able to ferment lactose 2)Specimen A is likely to be Escherichia coli (E. coli) 3)Specimen A is most likely Gram-negative 4)Specimen B is most likely Gram-negative 5)Specimen B is able to ferment lactose
Two different bacterial samples, A and B, were inoculated into the motility media shown here. http://session.masteringmicrobiology.com/problemAsset/1556544/1/motility_07.jpg Based on your observation of the pictured specimens select ALL appropriate statements. Specimen A is motile Specimen A is nonmotile Specimen B is motile Specimen B is nonmotile
1)Specimen A is nonmotile 2)Specimen B is motile
Two different bacterial samples, A and B, were grown on Gelatin deeps. This is a picture of the test results. http://session.masteringmicrobiology.com/problemAsset/1556563/1/gelatin_hydrolysis_02.jpg Select ALL appropriate statements regarding the pictured Gelatin test results. Specimen A produced gelatinase Specimen A did not produce gelatinase Specimen A hydrolyzed gelatin Specimen B produced gelatinase Specimen B did not produce gelatinase Specimen B hydrolyzed gelatin
1)Specimen A produced gelatinase 2)Specimen A hydrolyzed gelatin 3)Specimen B did not produce gelatinase
Two different bacterial samples, A and B, were analyzed with the Voges-Poskauer (VP) test. The results are pictured here. http://session.masteringmicrobiology.com/problemAsset/1556552/1/Vogues_Proskauer_02.jpg Select ALL appropriate statements regarding the pictured oxidase test results. Specimen A fermented glucose and formed acetoin (acetylmethylcarbinol). Specimen A fermented glucose and formed neutral end-products. Specimen A had a positive result for the VP test. Specimen B fermented glucose and formed acetoin (acetylmethylcarbinol). Specimen B is fermented glucose and formed neutral end-products. Specimen B had a positive result for the VP test.
1)Specimen B fermented glucose and formed acetoin (acetylmethylcarbinol). 2)Specimen B is fermented glucose and formed neutral end-products. 3)Specimen B had a positive result for the VP test.
Observing carbohydrate fermentation A Lactose Fermentation test was performed on two different bacterial samples, A and B. Based on your observations what can you conclude? http://session.masteringmicrobiology.com/problemAsset/1556527/1/carbohydrate_fermentation_test_14.jpg Based on your observation of the pictured Lactose Fermentation tests, choose all appropriate statements. Test organism A ferments lactose Test organism A produced gas Test organism A lowered the pH of the medium Test organism B does not ferment lactose Test organism B produced gas Test organism B lowered the pH of the medium
1)Test organism A ferments lactose 2)Test organism A produced gas 3)Test organism A lowered the pH of the medium 4)Test organism B does not ferment lactose
Use the micrograph of the Gram stain to draw conclusions and make predictions about the indicated bacterium. http://session.masteringmicrobiology.com/problemAsset/1556515/1/mixed_Gram_03.jpg Based on your observation of the indicated bacterium in this Gram stain, select ALL appropriate statements. The bacteria have a staph arrangement. The bacteria pictured are spirochetes. The indicated bacterium is Gram-negative. The indicated bacterium is Gram-positive. Eosin Methylene Blue (EMB) or MacConkey agar would NOT be good choices of media to grow the indicated bacteria. The indicated bacteria produce endotoxin (also known as lipopolysaccharide, LPS). The bacteria pictured are bacilli. The bacteria pictured are cocci.
1)The bacteria have a staph arrangement. 2)The indicated bacterium is Gram-positive. 3)Eosin Methylene Blue (EMB) or MacConkey agar would NOT be good choices of media to grow the indicated bacteria. 4)The bacteria pictured are cocci.
A specimen was inoculated onto the Triple Sugar Iron (TSI) medium pictured here. http://session.masteringmicrobiology.com/problemAsset/1556487/1/TSI_07.jpg Based on your observation of the pictured TSI (Triple Sugar Iron) medium select ALL appropriate conclusions. The bacterium is able to ferment glucose. The pH of the agar decreased following incubation. The bacteria is Gram-positive. The bacterium is unable to ferment lactose and/or sucrose. Hydrogen sulfide (H2S) was produced.
1)The bacterium is able to ferment glucose. 2)The pH of the agar decreased following incubation. 3)The pH of the agar decreased following incubation.
Interpreting biochemical test results (observations versus conclusions) Part A A specimen was inoculated onto the MacConkey agar pictured here. http://session.masteringmicrobiology.com/problemAsset/1556523/1/lactose_fermentation_on_MacConkey.jpg Based on your observation of the pictured MacConkey medium, select ALL appropriate conclusions . (Recall that an observation and a conclusion are different. An observation is simply what you see; conclusions are statements of what you learned from your observations.) The bacteria grew The bacterium is most likely Gram-negative The bacteria ferments lactose The bacterium is unable to ferment sucrose The bacteria is most likely Gram-positive The bacteria has a red/pink pigmentation
1)The bacterium is most likely Gram-negative 2)The bacteria ferments lactose
Interpreting biochemical test results (observations versus conclusions) Part A A specimen was inoculated onto the Triple Sugar Iron (TSI) medium pictured here. http://session.masteringmicrobiology.com/problemAsset/1556491/1/M_luteus_on_TSI_01.jpg Based on your observation of the pictured TSI (Triple Sugar Iron) medium select ALL appropriate conclusions . (Recall that an observation and a conclusion are different. An observation is simply what you see; conclusions are statements of what you determined based on your observations.) There is a black coloration in the butt of the tube. The bacterium is unable to ferment glucose. Hydrogen sulfide (H2S) was produced. The bacterium is unable to ferment lactose and/or sucrose. The butt of the medium is red. The slant of the medium is red. The bacteria growing on the slant is yellow. The pH of the agar decreased following incubation.
1)The bacterium is unable to ferment glucose. 2)The bacterium is unable to ferment lactose and/or sucrose.
Use the micrograph of the Gram stain to draw conclusions and make predictions about the indicated bacterium. http://session.masteringmicrobiology.com/problemAsset/1556516/2/1mixed_Gram_01.jpg Based on your observation of the indicated bacterium in this Gram stain, select ALL appropriate statements. The indicated bacterium is a spirochete The indicated bacterium is a bacillus The indicated bacterium has a strepto- formation The indicated bacterium is Gram-positive Eosin Methylene Blue (EMB) or MacConkey agar would NOT be good choices of media to grow the indciated bacterium The indicated bacterium produces endotoxin (also known as lipopolysaccharide, LPS) The indicated bacterium is Gram-negative
1)The indicated bacterium is a bacillus 2)The indicated bacterium has a strepto- formation 3)The indicated bacterium is Gram-positive 4)Eosin Methylene Blue (EMB) or MacConkey agar would NOT be good choices of media to grow the indciated bacterium
Item 3 Flagella arrangement Observe the micrograph and draw conclusions about the indicated bacterium. http://session.masteringmicrobiology.com/problemAsset/1556480/1/Flagella_06.jpg Based on your observation of the indicated bacterium in this micrograph, select ALL appropriate statements. The indicated bacterium has a lophotrichous flagella arrangement. The indicated bacterium is motile. The indicated bacterium has a monotrichous flagella arrangement. The indicated bacterium has a peritrichous flagella arrangement. The indicated bacterium has cilia. The indicated bacterium has an amphitrichous flagella arrangement.
1)The indicated bacterium is motile. 2)The indicated bacterium has a peritrichous flagella arrangement.
Part A Observe the micrograph and draw conclusions about the indicated bacterium. http://session.masteringmicrobiology.com/problemAsset/1556486/1/capsule_04.jpg Based on your observation of the indicated bacterial structure in this micrograph, select ALL appropriate statements. The indicated structure could serve as a virulence factor. The indicated structure is a slime layer. The indicated structure can be used for adhesion. The indicated structure is a capsule. The indicated structure is just a microscopy artifact. The indicated bacterium is resistant to drying (desiccation).
1)The indicated structure could serve as a virulence factor. 2)The indicated structure can be used for adhesion. 3)The indicated structure is a capsule. 4)The indicated bacterium is resistant to drying (desiccation).
A Catalase test was done on an unknown specimen. Observe the pictured result and answer the following question. http://session.masteringmicrobiology.com/problemAsset/1556556/1/catalase_test_03.jpg Select ALL appropriate statements regarding the pictured Catalase test result. The organism can convert hydrogen peroxide to water and oxygen. The organism does not produce catalase. The organism produces catalase. The organism can convert hydrogen peroxide to hydrogen sulfide. The organism is probably a strict anaerobe.
1)The organism can convert hydrogen peroxide to water and oxygen. 2)The organism produces catalase.
An unknown specimen was grown on Mannitol Salt agar (MSA). Observe the pictured result and answer the following question. http://session.masteringmicrobiology.com/problemAsset/1556558/1/MSA_02.jpg Select ALL appropriate statements regarding the pictured Mannitol Salt agar (MSA) test result. The organism tested is most likely Escherichia coli (E. coli). The organism tested is able to grow in the presence of high salt. The organism tested does not ferment mannitol. The organism tested is possibly a type of Staphylococci. The organism tested ferments mannitol.
1)The organism tested is able to grow in the presence of high salt. 2)The organism tested is possibly a type of Staphylococci. 3)The organism tested ferments mannitol.
Analyzing slide of negative stained bacteria Part A What can you conclude about the pictured specimen? http://session.masteringmicrobiology.com/problemAsset/1556521/1/neg_stain_coccus.jpg Based on your observation of this stained specimen, select ALL appropriate statements. The pictured bacteria are cocci This is a picture of a negative stained specimen The bacteria would not have been heat fixed in the preparation of this slide This is a picture of a Gram stained specimen The pictured bacteria are bacilli
1)The pictured bacteria are cocci 2)This is a picture of a negative stained specimen 3)The bacteria would not have been heat fixed in the preparation of this slide
What can you conclude about the Gram stained specimen? http://session.masteringmicrobiology.com/problemAsset/1556517/1/B_pertussis_diplococci_01.jpg Based on your observation of this Gram stained specimen, select ALL appropriate statements. The pictured bacteria are most likely non-acid fast. The pictured bacterium is Gram positive The pictured bacteria are diplococci It can be ruled out that this specimen is taxonomically found in the Staphylococcus genus. The pictured bacteria have strep arrangement The pictured bacteria have a staph arrangement The pictured bacteria produce lipopolysaccharide (LPS), also known as endotoxin.
1)The pictured bacteria are most likely non-acid fast. 2)The pictured bacteria are diplococci 3)It can be ruled out that this specimen is taxonomically found in the Staphylococcus genus. 4)The pictured bacteria produce lipopolysaccharide (LPS), also known as endotoxin.
What can you conclude about the Acid-Fast stained specimen? http://session.masteringmicrobiology.com/problemAsset/1556519/1/mycobacteria_(acid_fast_stain)_01.jpg Based on your observation of this acid-fast stained specimen, select ALL appropriate statements. The pictured bacteria is probably Gram-negative The pictured bacteria have mycolic acid in their cell walls This bacteria probably makes endospores The pictured bacteria are acid-fast The pictured bacteria probably produce lipopolysaccharide (LPS), also known as endotoxin. The pictured bacteria are non-acid-fast The pictured bacteria are possibly a type of mycobacteria
1)The pictured bacteria have mycolic acid in their cell walls 2)The pictured bacteria are acid-fast 3)The pictured bacteria are possibly a type of mycobacteria
Interpreting Gram stain images Part A Use the micrograph of the Gram stain to draw conclusions and make predictions about the pictured bacterium. http://session.masteringmicrobiology.com/problemAsset/1556514/1/gram_neg_cocci.jpg Based on your observation of the Gram stained bacterial specimen, select ALL appropriate statements. The pictured bacteria produce endotoxin (also known as lipopolysaccharide, LPS). The indicated bacterium is Gram-negative. Eosin methylene blue (EMB) or MacConkey agar would NOT be good choices of media to grow the pictured bacteria. The indicated bacterium is Gram-positive. The bacteria pictured are bacilli. The bacteria pictured are spirochetes. The bacteria pictured are cocci.
1)The pictured bacteria produce endotoxin (also known as lipopolysaccharide, LPS). 2)The indicated bacterium is Gram-negative. 3)The bacteria pictured are cocci.
What can you conclude based on your observation of the pictured Sucrose Fermentation test? http://session.masteringmicrobiology.com/problemAsset/1556528/1/carbohydrate_fermentation_test_09.jpg Based on your observation of the pictured Sucrose Fermentation test, choose all appropriate statements. The test organism ferments sucrose The test organism is unable to ferment sucrose The test organism lowered the pH of the medium The test organism raised the pH of the medium The test organism produced gas The test organism did not produce gas
1)The test organism ferments sucrose 2)The test organism lowered the pH of the medium 3)The test organism produced gas
Observe the pictured Sucrose Fermentation test. http://session.masteringmicrobiology.com/problemAsset/1556531/1/carbohydrate_fermentation_test_04.jpg Select the three best hypotheses that could explain why the broth in the Durham tube appears yellow while the rest of the broth appears red. The test organism ferments sucrose best under reduced oxygen conditions. The sample was incubated less than 24 hours, which allowed for only limited fermentation. The media was contaminated. The organism is an obligate aerobe and therefore can only grow inside the Durham tube. The media was prepared wrong. The organism is limited in its ability to ferment sucrose. Since diffusion is restricted within the Durham tube and it contains only a small volume of media, it turned yellow first. The test organism did not ferment sucrose.
1)The test organism ferments sucrose best under reduced oxygen conditions. 2)The sample was incubated less than 24 hours, which allowed for only limited fermentation. 3)The organism is limited in its ability to ferment sucrose. Since diffusion is restricted within the Durham tube and it contains only a small volume of media, it turned yellow first.
An unknown specimen was grown on Indole media. Based on your observation of this specimen choose the appropriate statements. http://session.masteringmicrobiology.com/problemAsset/1556561/1/Indole_negative_01.jpg Select ALL appropriate statements regarding the pictured Indole test. This is a picture of a negative test result. This is a picture of a positive test result. This test is a part of the IMViC panel of tests The organism tested fermented indole. The organism tested converts tryptophan to indole. This media is inoculated by stabbing the agar in the tube.
1)This is a picture of a negative test result. 2)This test is a part of the IMViC panel of tests 3)This media is inoculated by stabbing the agar in the tube.
Below is a Glucose Fermentation test. http://session.masteringmicrobiology.com/problemAsset/1556530/1/carbohydrate_fermentation_test_08.jpg Choose all appropriate statements about the Glucose Fermentation test. This test detects a fermentation reaction This media is inoculated using an inoculating loop The test contains phenol red which turns yellow under acidic conditions This media is inoculated with a mixed culture The mouth of the tube should be flamed prior to inoculation and immediately before capping the tube This is a selective media This test gives information about Gram property
1)This test detects a fermentation reaction 2)This media is inoculated using an inoculating loop 3)The test contains phenol red which turns yellow under acidic conditions 4)The mouth of the tube should be flamed prior to inoculation and immediately before capping the tube
Part F You inoculate an organism onto blood agar and observe a clear zone surrounding the bacterial growth. What type of hemolysis is indicated by this observation?
Beta hemolysis
Part E Which of the following describes an INCORRECT association regarding hemolytic activity?
Beta hemolysis; results in a greenish halo around the bacterial growth
Part G You observe colonies growing on EMB agar that are blue-black with a metallic green sheen. What species of bacteria is this likely to be?
E.coli
Part B What is the purpose of adding salt to mannitol salt agar?
High concentrations of salt inhibit the growth of non-halophilic organisms but allow for the growth of bacteria from the genus Staphylococci.
Part D Enriched blood agar permits the demonstration of the hemolytic properties of what group of microorganisms?
Streptococci
Part C You observe red colored colonies growing on MacConkey agar. What does this indicate about the organism?
The organism is able to ferment lactose.
Item 1: Part A You observe a yellow zone surrounding growth on mannitol salt agar. What does this indicate about the organism?
The organism is able to ferment mannitol.
