We spread 10⁹ bacteria on a plate with 25 µg streptomycin/mL media.Four colonies grow.These colonies contain bacteria that are A) wild-type. B) resistant to streptomycin. C) resistant to all antibiotics. D) able to grow in unusual circumstance. E) infected with bacteriophage.

Question

Quizplus · Accepted Answer

Since streptomycin was added to the media, it can be assumed that any bacteria that grow on the plate are resistant to it. Therefore, the colonies that grew must contain bacteria that are resistant to streptomycin. The other answer choices are not necessarily supported by the information given.

We Spread 109 Bacteria on a Plate with 25 µG

We Spread 10⁹ Bacteria on a Plate with 25 µG