BIOL 2420 LAB FINAL EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTION!!
what does iodine indicate in plate testing? Answer - whether the organism
produced alpha amylase
what does alpha amylase do? Answer - hydrolyzes starch to produce many
alpha-D-Glucose molecules
what does the enzyme urease do? Answer - this enzyme converts urea to
ammonia and increases pH drastically
which of the following media can be used to detect tryptophan degradation to
pyruvate and indole? Answer - SIM
Inoculation of a SIM tube indicates a color change to black. What can be
interpreted? Answer - sulfur reduction
A bacterium does not reduce nitrate at all. This bacterium is inoculated in a
nitrate broth tube for 24 hours. I add nitrate reagents A and B and, ten minutes
later, zinc (reagent C) What should I see? Answer - the broth would turn red
Fermentation of the disaccharides lactose and sucrose relied on enzymes to
hydrolyze them into two monosaccharides. Once these monosaccharides are
formed, they are fermented via _______, just as glucose is. Answer - glycolysis
, Gas production from fermentation in a phenol red broth tube is indicated by
the accumulation of gas into a bubble in a _______ tube. Answer - Durham
In a SIM tube, any H2S produced combines with _____, in the form of ferrous
ammonium sulfate to form ferric sulfide (FeS), a _________ precipitate.
Answer - Iron; black
Kovac's reagent reacts with ______ to form a _______ product. Answer -
Indole; red
Your TSI tube had a red slant and a yellow butt. This means that? Answer -
Glucose fermentation with acid production; proteins catabolized aerobically in
the slant with alkaline reversion products.
You inoculate a citrate tube with you unknown. Which of the following indicate
citrate utilization? Answer - Blue color and no color change but growth of
organism on citrate slant
T or F, A positive VP test indicates that your unknown was able to do a mixed
acid fermentation. Answer - False
Biosafety Level 1 (BSL-1) Answer - -not known to consistently cause diseases in
healthy adults
-ex. Lactobacillus casei, Bacillus subtilis, Rhizobium Ieguminosarum
Biosafety Level 2 (BSL-2) Answer - -Agents associated with human disease;
treatments and/or vaccines are usually available
-routes of transmission include percutaneous injury, ingestion, and mucous
membrane exposure
-ex. Staphylococcus aureus, Salmonella enterica, measles virus
ANSWERS WITH COMPLETE SOLUTION!!
what does iodine indicate in plate testing? Answer - whether the organism
produced alpha amylase
what does alpha amylase do? Answer - hydrolyzes starch to produce many
alpha-D-Glucose molecules
what does the enzyme urease do? Answer - this enzyme converts urea to
ammonia and increases pH drastically
which of the following media can be used to detect tryptophan degradation to
pyruvate and indole? Answer - SIM
Inoculation of a SIM tube indicates a color change to black. What can be
interpreted? Answer - sulfur reduction
A bacterium does not reduce nitrate at all. This bacterium is inoculated in a
nitrate broth tube for 24 hours. I add nitrate reagents A and B and, ten minutes
later, zinc (reagent C) What should I see? Answer - the broth would turn red
Fermentation of the disaccharides lactose and sucrose relied on enzymes to
hydrolyze them into two monosaccharides. Once these monosaccharides are
formed, they are fermented via _______, just as glucose is. Answer - glycolysis
, Gas production from fermentation in a phenol red broth tube is indicated by
the accumulation of gas into a bubble in a _______ tube. Answer - Durham
In a SIM tube, any H2S produced combines with _____, in the form of ferrous
ammonium sulfate to form ferric sulfide (FeS), a _________ precipitate.
Answer - Iron; black
Kovac's reagent reacts with ______ to form a _______ product. Answer -
Indole; red
Your TSI tube had a red slant and a yellow butt. This means that? Answer -
Glucose fermentation with acid production; proteins catabolized aerobically in
the slant with alkaline reversion products.
You inoculate a citrate tube with you unknown. Which of the following indicate
citrate utilization? Answer - Blue color and no color change but growth of
organism on citrate slant
T or F, A positive VP test indicates that your unknown was able to do a mixed
acid fermentation. Answer - False
Biosafety Level 1 (BSL-1) Answer - -not known to consistently cause diseases in
healthy adults
-ex. Lactobacillus casei, Bacillus subtilis, Rhizobium Ieguminosarum
Biosafety Level 2 (BSL-2) Answer - -Agents associated with human disease;
treatments and/or vaccines are usually available
-routes of transmission include percutaneous injury, ingestion, and mucous
membrane exposure
-ex. Staphylococcus aureus, Salmonella enterica, measles virus
