Question 1

Which of the following would be most useful in creating a phylogenetic tree of a taxon?

Accepted Answer

A)  morphological data from fossil and living species 
B)  a knowledge of color patterns in fossil and living species 
C)  a knowledge of mutation rates in modern species 
D)  morphological data from fossil species

Question 2

Eukaryotes that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their ________.

Accepted Answer

A)  plasmids 
B)  mitochondrial genomes 
C)  homologous genes that are poorly conserved 
D)  homologous genes that are highly conserved

Question 3

Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium?

Accepted Answer

A)  Plantae 
B)  Fungi 
C)  Animalia 
D)  Protista

Question 4

Phylogenetic trees constructed from evidence from molecular systematics are based on similarities in ________.

Accepted Answer

A)  morphology 
B)  the pattern of embryological development 
C)  biochemical pathways 
D)  mutations to homologous genes

Question 5

Use the figure to answer the following question.

Which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2 in the figure?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  E

Question 6

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 ________.

Accepted Answer

A)  homology 
B)  convergent evolution 
C)  common ancestry 
D)  retro-evolution by humans

Question 7

A phylogenetic tree is shown for the three domains of life (Eukarya, Archaea, and Bacteria). The tree branches in two directions from the first point, labeled Common ancestor of all life. One branch leads in the direction of Eukarya and Archaea, and the other branch leads to Bacteria. The branch leading to Eukarya and Archaea divide, one branch leading to each domain. The branch leading to Eukarya divides into four branches. One leads to Euglenozoans, and the other three lead to branching points. The first leads to Forams in one direction, and another branching point in the other that leads to Diatoms and Ciliates. The second branching point leads to Red algae in one direction, and a branching point that leads to green algae and land plants in the other direction. The third branching point leads to amoebas in one direction, and a branching point that leads to fungi and animals in the other direction. Land plants, Fungi and Animals are all highlighted.
Cyanobacteria were once called blue-green algae because they are photosynthetic. According to the phylogeny shown, the cyanobacteria are more closely related to gram-positive bacteria than to ________.

Accepted Answer

A)  proteobacteria 
B)  green algae 
C)  euglenozoans 
D)  crenarcheotes

Question 8

Use the following information to answer the question.
Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis) that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics.
In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species. (T. Monis, et al. 1999. Molecular systematics of the parasitic protozoan Giardia intestinalis. Mol. Biol. Evol. 16[9]:1135-44.)

By examining the phylogenetic tree diagrammed in the figure above, what conclusion can you draw about the species G. microti?

Accepted Answer

A)  It evolved before G. intestinalis. 
B)  It is more closely related to G. muris than to G. intestinalis. 
C)  It should not be labeled a species distinct from G. intestinalis. 
D)  It is part of a monophyletic group that also includes G. intestinalis.

Question 9

Which of the following statements best describes the rationale for applying the principle of maximum parsimony in constructing phylogenetic trees?

Accepted Answer

A)  Parsimony allows the researcher to "root" the tree. 
B)  Similarity due to common ancestry should be more common than similarity due to convergent evolution. 
C)  The molecular clock validates the principle of parsimony. 
D)  The outgroup roots the tree, allowing the principle of parsimony to be applied.

Question 10

The kingdom Monera was dismantled because of which of the following reasons?

Accepted Answer

A)  Some Monera contained nuclei in their cells. 
B)  The Monera, as originally constituted, contained both plants and animals. 
C)  The Monera, as originally constituted, was monophyletic. 
D)  Some, but not all, of the organisms in Monera contained DNA sequences that were similar to those of eukaryotes.

Question 11

The various taxonomic levels (for example, phyla, genera, classes) of the hierarchical classification system differ from each other on the basis of ________.

Accepted Answer

A)  how widely the organisms assigned to each are distributed throughout the environment 
B)  their inclusiveness 
C)  the relative genome sizes of the organisms assigned to each 
D)  morphological characters that are applicable to all organisms

Question 12

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). If the molecular data best reflect the evolutionary history of these two groups, then the morphological similarities of these two species is most likely due to ________.

Accepted Answer

A)  the inheritance of acquired characteristics 
B)  sexual selection 
C)  possession of analogous (convergent) traits 
D)  possession of shared primitive characters

Question 13

The best classification system is that which most closely ________.

Accepted Answer

A)  unites organisms that possess similar morphologies 
B)  conforms to traditional, Linnaean taxonomic practices 
C)  reflects evolutionary history 
D)  reflects the basic separation of prokaryotes from eukaryotes

Question 14

Use the figure to answer the following question.

The phylogenetic tree shown ________.

Accepted Answer

A)  depicts uncertainty about whether the bryophytes or the vascular plants evolved first 
B)  depicts an evolutionary hypothesis 
C)  includes evolution of convergent characteristics 
D)  indicates that seeds are a shared ancestral character of all vascular plants

Question 15

Use the figure to answer the following question.

If the figure above is an accurate depiction of relatedness, then which of the following should be an accurate statement?

Accepted Answer

A)  The entire tree is based on minimum parsimony. 
B)  If all species depicted here make up a taxon, this taxon is paraphyletic. 
C)  The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E. 
D)  Species A is the direct ancestor of both species B and species C.

Question 16

In Figure 26.4, which similarly inclusive taxon is represented as descending from the same common ancestor as Canidae?

Accepted Answer

A)  Felidae 
B)  Mustelidae 
C)  Carnivora 
D)  Lutra

Question 17

Use the following information to answer the question.
Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis) that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics.
In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species. (T. Monis, et al. 1999. Molecular systematics of the parasitic protozoan Giardia intestinalis. Mol. Biol. Evol. 16[9]:1135-44.)

Which of the following changes would a modern systematist be most likely to make after learning of the results of the rRNA analyses?

Accepted Answer

A)  continue to keep subgroups A-D as members of the species G. intestinalis 
B)  break the species G. intestinalis into four separate species, A, B, C, and D 
C)  combine subgroup D and G. microti into one species 
D)  combine all the subgroups of G. intestinalis (A-
D)  and G. microti to make one species

Question 18

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

Accepted Answer

A)  their common ancestor having been legless 
B)  a shared adaptation to an arboreal (living in trees) lifestyle 
C)  several instances of the legless condition arising independently of each other 
D)  individual lizards adapting to a fossorial (living in burrows) lifestyle during their lifetimes

Question 19

The question refers to the following table, which compares the percent sequence homology of four different parts (two introns and two exons) of a gene that is 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 another member of species A.
% Sequence Homology

Based on the tabular data, and assuming that time advances vertically, which phylogenetic tree is the most likely depiction of the evolutionary relationships among these five species?

Accepted Answer

A) 
 
B) 
 
C) 
 
D)

Question 20

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?

Accepted Answer

A)  mtDNA 
B)  rRNA genes 
C)  morphological 
D)  ecological

Exam 26: Phylogeny and the Tree of Life

Which of the following would be most useful in creating a phylogenetic tree of a taxon?

Eukaryotes that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their ________.

Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium?

Phylogenetic trees constructed from evidence from molecular systematics are based on similarities in ________.

Use the figure to answer the following question. Which extinct species should be the best candidate to serve as the outgroup for the clade whose common ancestor occurs at position 2 in the figure?

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 ________.

Which of the following statements best describes the rationale for applying the principle of maximum parsimony in constructing phylogenetic trees?

The kingdom Monera was dismantled because of which of the following reasons?

The various taxonomic levels (for example, phyla, genera, classes) of the hierarchical classification system differ from each other on the basis of ________.

The best classification system is that which most closely ________.

Use the figure to answer the following question. The phylogenetic tree shown ________.

Use the figure to answer the following question. If the figure above is an accurate depiction of relatedness, then which of the following should be an accurate statement?

In Figure 26.4, which similarly inclusive taxon is represented as descending from the same common ancestor as Canidae?

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

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?