The child only comes out as homozygous dominant (YY) for the trait in 1/4 boxes in the Punnett Square. This translates to the child having a 25% chance of being homozygous dominant for the trait.
Homozygous is when the two letters are the same and dominance is represented by capital letters. There is one square that has two capital letter so 1/4 is equal to 25%. Hope this helps
Some methods the scientists could use would be, monitoring the population of prey which the lionfish is known to consume, and also monitor the size/weight of the lionfish in order to understand how and why they are able to flourish.