Question #bf2f2

1 Answer
Feb 14, 2018

dd (homozygous recessive, dragon breath shows), Dd (heterozygous, dragon breath does not show), DD (homozygous dominant, dragon breath does not show).


The parents are "carriers" of dragon breath. This means that they are both heterozygous for dragon breath. That means the dragon breath does not show (it's recessive), but they still have the gene. Let's call the dragon breath gene "d," and the other, dominant gene "D." Using a Punnett Square:

(Note : dD and Dd are the same thing).

dd is homozygous recessive, and dragon breath shows. dD/Dd is heterozygous, and dragon breath doesn't show (remember, it's recessive). DD is homozygous dominant, and dragon breath doesn't show, because, the gene for it isn't there!