What do the circled letters on the outside of the Punnett square in the attached figure represent?

The circled letters represent the genotypes of the two parents

The top 2 letters (A a) is the genotype of one of the parents

The 2 letters on the far left (AA) is the genotype of the other parent

other information encoded in your genes might distinguish you from the others in the group

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101