In Drosophila, brown body colour (B) is dominant to black (b) and long wings (W) are dominant to short wings (w). A researcher crossed a male Drosophila with genotype "BBWW" with a female Drosophila with genotype "bbww". She then crosses two Drosophila of the F1 generation and draws the F2 Punnett square in her record book, which is shown below, and you have to fill in the blanks in her Punnett square.
