Biology

The correct answer is: A. Echinodermata & Cnidaria.

1. Analyze the distance of common ancestors for each option on the phylogenetic tree:

A.Echinodermata & Cnidaria:

Cnidaria branches off before the emergence of the “Bilateral symmetry” trait. Echinodermata is part of the group that has bilateral symmetry as a derived trait. The common ancestor of Echinodermata and Cnidaria is far back in the tree, at a relatively early - branching point.

B.Arthropoda & Chordata: Both Arthropoda and Chordata are part of the group that has bilateral symmetry. They share a more recent common ancestor compared to Echinodermata and Cnidaria as they are on branches that diverge fr...