Question

You would like to set up a similar test to the Ames test using a species of fungi. You start with a methionine auxotroph that is resistant to the antibiotic kanamycin. You then test the potential fungicidal compound X and grow your cells on a plate lacking methionine. Which of the following results would lead you to conclude that compound X is a mutagen? Can be multiple answers.
A. There are fewer cells around the compound X disk compared to a control plate without compound X.
B. There are more cells around the compound X disk compared to a control plate without compound X
C. The liquid culture of cells which were to be added to the plate with compound X grew more rapidly than normal.
D. Compound X caused the filter paper disk to turn red.

Answer 1

Answer:

A. There are fewer cells around the compound X disk compared to a control plate without compound X.

B. There are more cells around the compound X disk compared to a control plate without compound X

Explanation:

A mutagen is any chemical and/or physical factor that is able to induce mutations in the DNA sequence of the cells of an organism. In general, mutations have a deleterious effect on the phenotype. In consequence, it is expected that a mutagen would lead to a decrease in viability of the cells (for example, by causing a loss of function mutation in a growth factor and/or receptor that drives cell proliferation). Moreover, mutations may also cause gain-of-function mutations in genes that encode proteins associated with uncontrolled cell proliferation and survival, thereby increasing the number of cells around the compound X disk.