Question

5 multiple choice 20 points what does the root of a cladogram or phylogenetic tree represent? the most recent common ancestor of all organisms represented. the oldest living species that has not yet diverged. the extinction point of the oldest species on the tree. the last living species to evolve during the period represented by the tree.

Explanation:

A cladogram or phylogenetic tree's root represents the most recent common ancestor of all organisms depicted. It's the starting point from which divergence occurs. The other options are incorrect: the root isn't an extant (living) species (so "oldest living species..." is wrong), it's not an extinction point (as it's a common ancestor, not a species going extinct), and it's not the last - evolving species (it's the ancestral form from which others evolved).

Answer:

The most recent common ancestor of all organisms represented.