Question

in a cladogram, what occurs at a node?
a derived trait appears.
evolution is stopped.
an ancestor dies.
the cladogram ends.

Explanation:

Cladograms are diagrams showing evolutionary relationships. Nodes represent points where a lineage splits, which corresponds to the emergence of a new derived trait that distinguishes the new group from its ancestor. The other options are incorrect: evolution does not stop at nodes, nodes do not mark an ancestor's death, and cladograms end at terminal taxa, not nodes.

Answer:

A. A derived trait appears.