Exam 20: Phylogeny

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

The kingdom Protista is obsolete because it contains members of how many other kingdoms?

Which of the following are the best examples of homologous structures?

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

What is one common mistake taxonomists may make when attempting to place seemingly closely related species into a shared classification group?

When hypothesizing a possible phylogeny in order to classify taxa,scientists incorporate systematics to

In Figure 20.6 below,which similarly inclusive taxon descended from the same common ancestor as Canidae? Figure 20.6

Which of these four gene parts should allow the construction of the most accurate phylogenetic tree,assuming this is the only part of the gene that has acted as a reliable molecular clock?

The most important feature that permits a gene to act as a molecular clock is

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

How does a molecular clock measure time?

In addition to naming species,Linnaeus also grouped species into a hierarchy of increasingly inclusive categories.The largest category that would include closely related species is the

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

Researchers obtained the data depicted here by sampling human blood containing HIV and then isolating and sequencing genes within the human immunodeficiency virus's DNA.What does the line and shaded area that intersect the x-axis represent?

You discover a fossil with feathers on forelimbs,short hind limbs,and teeth.You conclude that this organism appears early on a phylogenetic tree for which group of organisms?

Sister taxa

This question refers to Table 20.1,which compares the % sequence homology of four different parts (two introns and two exons)of a gene found in five different eukaryotic species.Each part is numbered to indicate its distance from the promoter (for example,intron I is the one closest to the promoter).The data reported for species A were obtained by comparing DNA from one member of species A to the DNA of another member of species A. Table 20.1 -Based on the tabular data,and assuming that time advances vertically,which cladogram (a type of phylogenetic tree)is the most likely depiction of the evolutionary relationships among these five species?

When it acts upon a gene,which of the following processes consequently makes that gene an accurate molecular clock?

Please use the following information to answer the questions below. Traditionally,zoologists have placed birds in their own class,Aves.More recently,molecular evidence has shown that birds are more closely related to reptiles than their anatomy reveals.Genetically,birds are more closely related to crocodiles than crocodiles are to turtles.Thus,bird anatomy has become highly modified as they have adapted to flight,without their genes having undergone nearly as much change. -Taxonomically,what should be done with the birds?

Scientists discovered a fossil in China that belongs to a previously unknown species of an obscure group of small dinosaurs,related to primitive birds such as the famous Archaeopteryx.It had feathers,but they seemed too insubstantial to be useful in flight.Then the scientists said they recognized the unusually long,rodlike bone extending from each of the two wrists: curving structures possibly supporting an aerodynamic membrane.These scientists are grouping the found fossil with birds based on ________ structures.