If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?a. wolfb. domestic catc. liond. leopard

Explain the lock-and-key model of enzyme activity. What is incorrect about this model?

How do the extracellular filaments in plants differ from those in animals?a. Plant filaments resist compression forces; animal filaments resist pulling forces.b. Animal filaments consist of proteins; plant filaments consist of polysaccharides.c. Plant extracellular filaments never move; animal filaments can slide past one another.d. Plant filaments run parallel to one another; animal filaments crisscross.

What important assumption does parsimony make when assessing which phylogenetic tree is most accurate? Why was parsimony misleading in the case of the astragalus during the evolution of artiodactyls?

VISUAL SKILLS Based on the tree below, which statement is not correct?

a.Goats and humans form a sister group.b. Salamanders are a sister group to the group containing lizards, goats, and humans.c. Salamanders are as closely related to goats as to humans.d. Lizards are more closely related to salamanders than to humans.

You can use a 'one-snip test' to identify monophyletic groups—meaning that if you 'cut' any branch on a tree, everything that 'falls off' is a monophyletic group. Why is this valid?

In terms of structure, how do channel proteins differ from carrier proteins?

VISUAL SKILLS The relative lengths of the frog and mouse branches in the phylogenetic tree in Figure 26.13 indicate that a. frogs evolved before mice. b. mice evolved before frogs.c. the homolog has evolved more rapidly in mice.d. the homolog has evolved more slowly in mice.

If you were using cladistics to build a phylogenetic tree of cats, which would be the best choice for an outgroup?a. kangaroob. leopardc. domestic catd. iguana