"AP physics"

Yeast strains are ideal for genetic study because they are easy to grow and maintain, their life cycle is complete in approximately one week, and you can arrest different stages of the life cycle by growing it on different types of media.

Two strains of Escherichia coli (donor and host) with complementary sensitivities to Ampicillin and Streptomycin. Watch them trade traits via conjugation.

Ames test strain for detecting carcinogens. Causes infection in humans.