Critique the following statement: The absence of a trait cannot be used as a synapomorphy in phylogenetic analysis; only shared derived traits that are present in the clade can be used.

In a comparison of birds and mammals, the condition of having four limbs isa. a shared ancestral character.b. a shared derived character.c. a character useful for distinguishing birds from mammals.d. an example of analogy rather than homology.

To apply parsimony to constructing a phylogenetic tree,a. choose the tree that assumes all evolutionary changes are equally probable.b. choose the tree in which the branch points are based on as many shared derived characters as possible.c. choose the tree that represents the fewest evolutionary changes, in either DNA sequences or morphology.d. choose the tree with the fewest branch points.

Fill in the blanks on the phylogenetic tree (on the facing page) to show current hypotheses for the origin of multicellular organisms. a. b. c. d. e. f.

Fill in this concept map about systematics a.b. c. d. e.f.g

Where are protein components of the extracellular matrix synthesized?a. in the rough ERb. in the Golgi apparatusc. in the plasma membraned. in the extracellular layer itself

How are hypotheses about the evolutionary relationships among living organisms tested?

VISUAL SKILLS In Figure 26.4, which similarly inclusive taxon is represented as descending from the same common ancestor as Canidae?a. Felidaeb. Mustelidaec. Carnivorad. Lutra

Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes upa. a monophyletic taxon.b. an ingroup, with species U as the outgroup.c. a paraphyletic group.d. a polyphyletic group.