Q1. An enterprising pet store owner is attempting to create a pure strain of ultra-dwarf mice to sell as novelty pets. He breeds 10 pairs of ultra-dwarf mice and counts the different phenotypes seen in the offspring. (A wild-type mouse litter is 10 mice.) In the F1 generation, 50 are ultra-dwarf, and 25 are wild-type. Each time he breeds two ultra-dwarves he gets the same ratio.

1. What is going on?

2. Will he ever get a pure strain? If not, why with reason?

Q2. As Ben jumped on his bike and headed for the fresh water lake, his mom called after him, “Don’t swim if we have an electrical storm-it looks threatening”. That was a valid request. Why with reason?