Answer:
The correct answer would be -
50% heterozygous red flies and 50% recessive brown eyes flies in offspring
Explanation:
This is given that a species of fly has two traits for the eye red eye which is the dominant trait and can be represented by R and the brown eyes trait which is recessive and represented by r.
Given: heterozygous fly which means have both traits gene but as Red is dominant it will have red eyes mates with recessive brown eye fly.
Rr × rr
gametes: R, r and r, r
then,
  R    r
r  Rr  rr
r   Rr  rr
There is 50 % recessive brown eyes flies in offspring and 50% heterozygous red eys offspring.