In microbiology lab, you make three different culture plates: one general purpose plate, one selective media plate, and one differential media plate. Unfortunately, you forget to label the different plates, so you do not know which is which. To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria. After inoculation, you see that a particular plate has allowed both organisms to grow, but one has changed color. Which plate do you think this is?

a. It is impossible to distinguish between selective and differential media in this case. b. general purpose mediac. selective mediad. differential media

The correct answer is d. differential media

Explanation:

Differential media are used to distinguish between two microorganisms that are closely related. Differential media have some special and specific ingredients or indicators and nutrients which is used to differentiate between two different strains of bacteria by physical appearance like color.

For example, blood agar is the differential media that differentiate between the micro-organism who can lyse the blood cell and who cannot lyse blood.

So differential media allow us to grow both the organism but differentiate them on the basis of physical appearance like color, therefore, the correct answer is d. differential media.