Please answer the photo is above thank you.

the first box is recessive, other three are dominant. the first and third of the second row are heterogeneous and the second and fourth are homogeneous. first and fourth one of the third row are homogeneous dominant, the second one is heterogeneous, the third one is homogeneous recessive. of the fourth row, it goes; purple, purple and white, and white. for the last question the possible genotypes are BB, BB on top, Bb, Bb, on bottom. The phenotype can be black and grey or black and black and white spotted. the percent chance is 50% for both and 1:1

Explanation:

the answer is b.) hydrogen bonds between bases.