Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

You plated an unknown yeast auxotrophic mutant on MD media and left it in the in

ID: 199706 • Letter: Y

Question

You plated an unknown yeast auxotrophic mutant on MD media and left it in the incubator for a week. At the end of the week, you had no growth on the plate. What is the MOST LIKELYexplanation?

You irradiated the cells with a sufficiently high dosage of UV that they all died.

You left the plate in the incubator too long.

The cells required a nutrient that was not present in the media.

You irradiated the cells with a sufficiently low dosage of UV that they all died.

You irradiated the cells with a sufficiently high dosage of UV that they all died.

You left the plate in the incubator too long.

The cells required a nutrient that was not present in the media.

You irradiated the cells with a sufficiently low dosage of UV that they all died.

Explanation / Answer

The cells required a nutrient that was not present in the media - Since, it is an auxotrphic mutant, the yeast may not have been able to produce a nutrient required for its normal growth and also the same nutrient may not have been included in the media used for culturing the organism.