Chapter 26

D) Protista

Based on cladistics, which eukaryotic kingdom is polyphyletic and, therefore, unacceptable?

B) On a phylogenetic tree whose branch lengths are proportional to the amount of genetic change, the branches of the extremophiles should be shorter than the non-extremophilic archaeans.

A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on the primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?

C) chimpanzees and humans

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

A) Tree 1

Applying the principle of parsimony to the trait "ability to fly," which of the two phylogenetic trees above is better?

D) Lizards are more closely related to salamanders than to humans.

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

B) Salamanders are a sister group to the group containing lizards, goats, and humans.

Based on this tree, which statement is correct?

D) It is part of a monophyletic group that also includes G. intestinalis.

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

A) orthologous genes

Concerning growth in genome size over evolutionary time, which of these is LEAST associated with the others?

A) proteobacteria

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 ________.

D) homologous genes that are highly conserved

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 _____.

C) forams, red algae, and amoebas

Examine the figure. If you were a graduate student trying to develop a thesis project that would resolve polytomies, which of the following groups would you study?

B) Trait 2

Given that phylogenies are based on shared derived characteristics, which of the following traits is useful in generating a phylogeny of species W, X, Y, and Z? Species W Species X Species Y Species Z Trait 1 A A A A Trait 2 A A B B Trait 3 A B C D

B) paraphyletic

Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about fifteen million years ago. Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time. 34) Assuming chimps and gorillas are humans' closest relatives, removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes _____.

A) redraw the phylogeny to show eukaryotes sharing a more recent common ancestor with bacteria than archaea

If additional DNA sequence evidence shows that yeast genes for synthesizing proteins are more similar to protein-synthesizing genes in bacteria than those in archaea, a modern systematist would ________.

D) D and E

If organisms A, B, and C belong to the same class but to different orders and if organisms C, D, and E belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

C) The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E.

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

A) If all species depicted here make up a taxon, this taxon is monophyletic.

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

A) wolf

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

C) wolf

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

B) convergent evolution

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 _____.

A) The same phylogeny would be unlikely.

Imagine that a phylogeny was developed for a group of mammals based on bone structure. Which of the following statements would be a reasonable prediction about a phylogeny for the same group of species based on similarities and differences in the structure of a particular enzyme?

B) Mustelidae

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

A) a shared ancestral character

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

A) a shared ancestral character.

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

C) 3 and 4

In the phylogenetic trees above, numbers represent species and the same species are shown in both trees. Which two species are represented as sister species in Tree 2 but are not shown as sister species in Tree 1?

C) phylogenies

Linnaeus believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with _____.

D) a significant proportion of mutations are not acted upon by natural selection

Molecular clocks are more reliable when ________.

D) mutations to homologous genes

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

D) E, F, and G

Refer to the figure above. Which of the following forms a monophyletic group?

D) inferring evolutionary relatedness from the number of sequence differences

Regarding these sequence homology data, the principle of maximum parsimony would be applicable in _____.

A) convergent evolution

Some beetles and flies have antler-like structures on their heads, much like male deer do. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of _____.

C) possession of analogous (convergent) traits

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 _____.

C) reflects evolutionary history

The best classification system is that which most closely _____.

C) structural analogies

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as _____.

B) The origin of the three domains appears as a polytomy.B) The origin of the three domains appears as a polytomy.

The following questions refer to this phylogenetic tree, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer. A possible phylogenetic tree for the three domains of life. 58) If the early history of life on Earth is accurately depicted by the figure above, then which statement is most in agreement with the hypothesis proposed by this tree?

D) molecular genetics

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

D) Some, but not all, of the organisms in Monera contained DNA sequences that were similar to those of eukaryotes.

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

B) mitochondrial DNA

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma. These species have apparently undergone speciation from ancestral stock since the last glacial retreat about ten thousand years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?

C) several instances of the legless condition arising independently of each other

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

C) a reliable average rate of mutation

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

B) depicts an evolutionary hypothesis

The phylogenetic tree shown ________.

D)

The questions below refer to the following table, which compares the % 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 Species Intron I Exon I Intron VI Exon V A 100% 100% 100% 100% B 98% 99% 82% 96% C 98% 99% 89% 96% D 99% 99% 92% 97% E 98% 99% 80% 94% 35) 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?

C) Intron VI

The questions below refer to the following table, which compares the % 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 Species Intron I Exon I Intron VI Exon V A 100% 100% 100% 100% B 98% 99% 82% 96% C 98% 99% 89% 96% D 99% 99% 92% 97% E 98% 99% 80% 94% 52) Which of these four gene parts should allow the construction of the most accurate phylogenetic tree, assuming that this is the only part of the gene that has acted as a reliable molecular clock?

D) having an extra copy of a gene permits modifications to the copy without loss of the original gene product

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that _____.

D) the homolog has evolved more slowly in mice.

The relative lengths of the frog and mouse branches in the phylogenetic tree in Figure 26.13 indicate that

A) the legless condition found in various lineages of extant lizards

The term convergent evolution is most applicable to which of the following features?

B) their inclusiveness

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

D) derived character of mammals, but only if cynodonts are reclassified as mammals

There is some evidence that reptiles called cynodonts may have had whisker-like hairs around their mouths. If true, then hair is a shared _____.

D) Eukaryotes are more similar to archaea than to bacteria.

These data would support which of the following conclusions?

c. a paraphyletic group.

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

C) choose the tree that represents the fewest evolutionary changes, in either DNA sequences or morphology.

To apply parsimony to constructing a phylogenetic tree,

C) choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

To apply the principle of maximum parsimony to construction of a phylogenetic tree, ________.

D) paraphyletic

Use the following information to answer the question(s) below. 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. According to the phylogenetic tree in the figure above, G. intestinalis constitutes a _____ group.

B) horizontal gene transfer from bacterium to eukaryotes

Use the following information to answer the question(s) below. Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "chromatophores." The chromatophores are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants. 56) A crucial photosynthetic gene of the cyanobacterium that gave rise to the chromatophore is called psaE. This gene is present in the nuclear genome of the cercozoan, but is not in the genome of the chromatophore. This is evidence of _____.

D) lizards, pterosaurs, dinosaurs, birds, synapsids, monotremes, marsupials, rodents, and primates

We know the streamlined bodies shown in the figure above are examples of homoplasy. If the following groups also had streamlined bodies, which of the groupings would give the most support to this body type being homologous?

B) rRNA genes

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?

A) Plantae

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

A) A

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 above?

B) break the species G. intestinalis into four separate species, A, B, C, and D

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

D) polyphyletic taxa and paraphyletic taxa

Which of the following is (are) problematic when the goal is to construct phylogenies that accurately reflect evolutionary history?

C) genome size

Which of the following items is MOST likely to form a simple linear relationship with the number of gene-duplication events, when placed as the label on the vertical axis of the following graph?

A) bones in the bat wing and bones in the human forelimb

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

A) Horizontal gene transfer was quite common in the early stages of evolution of life on Earth.

Which of the following statements about horizontal gene transfer is accurate?

B) Similarity due to common ancestry should be more common than similarity due to convergent evolution.

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

B) Genes from prokaryotes have been acquired by some eukaryotes; these genes can allow survival in extreme environments.

Which of the following statements is accurate, at least according to our present knowledge?

A) Descendant groups (branches) from the same node likely share many derived characters.

Which of the following statements is true about a phylogeny, as represented by a phylogenetic tree?

C)

Which of the following trees, if any, depicts the same relationship among species as shown above?

D) morphological data from fossil species

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

D) natural selection

Which of the following would, if it had acted upon a gene, prevent this gene from acting as a reliable molecular clock?

A) endosymbiosis

Which of these processes can be included among those responsible for the horizontal components of the figure above?

D) the trunk of the tree

Which portion of the figure above may ultimately be better depicted as a "ring"?

D) share a very recent common ancestor

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves _____.

C) III

Which tree depicts the closest relationship between zygomycetes and chytrids?

A) I

Which tree depicts the microsporidians as a sister group of the ascomycetes?

A) I

Which tree shows the greatest evolutionary distance between chytrids and ascomycetes?

A) to serve as an outgroup

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?