Bio Chapter 20 Practice Questions

In a comparison of birds and mammals, the condition of having four limbs is.....

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 up

If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?

Which of the following taxonomic categories contains all the others listed here?

The legless condition that is observed in several groups of extant reptiles is the result of

Linnaeus was a "fixist" who believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with

Animals that possess homologous structures probably _____.

Systematists have used a wide variety of traits to reconstruct the phylogenies of particular groups of organisms. Which one of the following traits produces a good estimates of phylogeny?

If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to

The importance of computers and of computer software to modern cladistics is most closely linked to advances in

By definition a clade is _____.

Fossil evidence indicates that some dinosaurs had feathers. If birds are indeed descended from dinosaurs, feathers are what kind of character?

Which of the following is true of all horizontally oriented phylogenetic trees, where time advances to the right?

Cladograms (a type of phylogenetic tree) constructed from evidence from molecular systematics are based on similarities in

There is some evidence that reptiles called cynodonts may have had whisker-like hairs around their mouths. If true, then what can be properly said of hair?

Molecular clocks are based on the idea that _____

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of

Neutral theory proposes that

Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult?

Why do researchers use rRNA in investigations of relationships between taxa that diverged hundreds of millions of years ago?

Which kind of DNA should provide the best molecular clock for determining the evolutionary relatedness of several species whose common ancestor became extinct billions of years ago?

Which kingdom has been replaced with two domains?

What process actually increases the number of genes in an organism's genome?

Which observation supports the position of eukaryotes at the convergence of the "ring of life"?