The current classification system used by biologists is
A)complex and unchanging. B)universally accepted by all biologists. C)based on four generalized types of living organisms: the Bacteria, the Archaea, the Eukarya, and the Protista. D)updated and revised whenever new information becomes available.
DNA analysis has become a useful tool for understanding the relationships between organisms because
A)shared characteristics are usually the products of shared genes. B)DNA is used by all organisms to collect energy. C)only mammals have DNA. D)knowing the DNA codes means biologists no longer have to use taxonomy.
The organisms most distant from the base of an evolutionary tree are
A)unrelated to the organisms separated by one or more branch points. B)less primitive than the organisms lower on the tree. C)those that have evolved most recently. D)chronologically older than the organisms lower on the tree.