HSA 2006 Biology Item 18

In a species of fly, the allele for red eyes (R) is dominant to the allele for brown eyes (r). Red eye color in the flies is not sex-linked. Students crossed male and female flies that had red eyes and recorded the eye color of their offspring. Their data are shown below.

Using the data in the table, what is the approximate ratio of red eyed offspring to brown eyed offspring?

1. 1:1
2. 2:1
3. 3:1
4. 4:1