Microbiology Pt. 2

Question 1

differential agar that allows detection of hemolysis

Answer 1

Blood

Question 2

non-selective and non-differential agar on which all non-fastidious microorganisms can grow

Answer 2

Nutrient

Question 3

selective agar that only grows Gram-negative bacteria and is differential for lactose fermentation, this agar is used to detect coliforms such as E coli, which appears metallic green on this agar

Answer 3

Eosin Methylene Blue (EMB)

Question 4

alpha-hemolysis appearance on Blood Agar

Answer 4

green

Question 5

beta-hemolysis appearance on Blood Agar

Answer 5

colorless ring

Question 6

gamma-hemolysis appearance on Blood Agar

Answer 6

red (no change)

Question 7

fermentation of lactose

Answer 7

produces acid, which changes the local pH, changing the color of the dyes. used to isolate fecal coliforms (bacteria from colon)

Question 8

hemolysis

Answer 8

rupture of red blood cells

Question 9

colony

Answer 9

visible cluster of identical bacteria that grew from one original bacterium

Question 10

lawn

Answer 10

a dense covering of bacteria on a plate due to the colonies growing into each other

Question 11

turbid

Answer 11

liquid broth that is cloudy due to bacterial growth

Question 12

Serial dilution

Answer 12

performed to reduce the number of cells in a culture, a stepwise dilution of a substance in a solution

Question 13

more dilution means…

Answer 13

fewer colonies

Question 14

CFU

Answer 14

colony-forming units, each bacteria can form a colony, s # bacteria,

Question 15

CFU/ml

Answer 15

number of colonies per ml plated, total dilution factor