1. Genomes and mutagenesis

2. Figure 9.15

3. The Ames test relies on a mutant bacterial strain that is defective in hisG. - Cannot grow on a medium lacking histidine Identifying Mutagens - A mutagen-containing disk is placed on an agar plate with the mutant. - Mutagen causes reversion mutations, and colonies start to appear around the disk. Figure 9.22

4. The Ames assay can be modified to test for the mutagenicity of chemicals processed in the liver. Figure 9.23

6. Transposons are complex transposable elements that carry additional genes (e.g., drug resistance). Mobile Genetic Elements Figure 9.34

7. Fig. 11-33 Gene A Transposon Transposition Disrupted gene 2 Gene AGene 1Gene 3 Chromosome Gene 1Gene 2Gene 3 Chromosome