Probability and Multiple Trait Inheritance. Punnett Squares and Probability. All ratios established from a Punnett square, represent probabilities. Probability can be thought of as a score out of 1 that indicates the likelihood of an event. 0.50 event will occur half of the time
H = normal hemoglobin h = thalassemia
Hh X Hh, what is the probability that they will have an affected child?