The Edit Genetics panel is the place to store the genetic characteristics of a person including their blood group (ABO and Rhesus (Rh) blood group system), hair colour and eye colour (left and right eyes can be defined separately).
Fig 1. The Edit Genetics panel.
Other genetic information
You can store other genetic information as a note. For example you could store information about ancestral blood lines or medical traits.
Prediction of genetic traits is not carried out by My Family Tree because although some genetic traits can be predicted, this prediction is almost always a probability. For example, using a simple model, a blue eyed parent and a brown eyed parent would have 25% chance of having a blue eyed child and 75% of having a brown eyed child. This means that if they had 4 children, 3 would be expected to have brown eyes and 1 blue eyes. It is however entirely possible that all their children happen to have blue eyes or that they don't have brown or blue eyes at all.