The tiny fruit fly is a superstar of genetics research. Thousands of experiments have explored how flies inherit traits. Wing shape, body color, eye color, and head shape are a few traits under investigation. Fruit flies make good study subjects because they are inexpensive, take little space, and breed quickly. In addition, humans and fruit flies share 75% of their disease genes. By studying fruit-fly genetics, we can learn about human illness.
Short-winged fruit flies studied in the lab cannot fly because they have an allele that causes them to grow tiny wings (w). Normal fruit flies, known as “wild-types”, have fully functional wings (W). The wild-type wing is the dominant allele.
If you cross one short-winged fly (ww) with a wild-type fly (WW), what is the probability of getting a short-winged offspring in the F1 generation?