Campbell Biology in Focus, 2e (Urry)
Chapter 20 Phylogeny
20.1 Multiple-Choice Questions
1) 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
A) genus.
B) class.
C) order.
D) domain.
2) A polytomy on a phylogenetic tree represents
A) sister taxa.
B) a lineage that diverges from all other lineages in its group.
C) most recent common ancestor.
D) insufficient data to determine lineage relationship.
3) The various taxonomic levels (genera, classes, etc.) of the hierarchical classification system
differ from each other on the basis of
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.
4) If organisms A, B, and C belong to the same class but to different orders and if organisms D,
E, and F 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?
A) A and B
B) A and C
C) B and D
D) D and F
5) 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
A) classifying organisms using the morphospecies concept.
B) the scientific discipline known as taxonomy.
C) phylogenies.
D) nested, ever-more inclusive categories of organisms.
6) How does phylogeny differ from systematics?
A) in classifying organisms
B) in the classification of organisms by evolutionary history
C) in the naming of organisms
D) in the hierarchy of classification
7) Sister taxa
A) represent the common ancestor of taxa.
B) represent groups of organisms that share an immediate common ancestor.
C) represent a polytomy.
D) diverge from all other lineages early in the history of the group.
8) What evidence suggests that limbless bodies are the result of convergent evolution of snakes
and lizards?
A) Snakes and lizards with limbless bodies evolved from different ancestors of legged lizards.
B) Limbless bodies do not share a most recent common ancestor.
C) Three traits are shared by all snakes.
D) Species adapted to their environments.
9) The term homoplasy is most applicable to which of the following features?
A) the five-digit condition of human hands and bat wings
B) the β hemoglobin genes of mice and humans
C) the fur that covers Australian moles and North American moles
D) the bones of bat forelimbs and the bones of bird forelimbs
10) Which of the following are the best examples of homologous structures?
A) bones in the bat wing and bones in the human forelimb
B) owl wing and hornet wing
C) bat wing and bird wing
D) eyelessness in the Australian mole and eyelessness in the North American mole
11) 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
A) inheritance of acquired characteristics.
B) sexual selection.
C) inheritance of shared derived characters.
D) possession of analogous structures.
12) The importance of computers and of computer software to modern cladistics is most closely
linked to advances in
A) radiometric dating.
B) fossil discovery techniques.
C) Linnaean classification.
D) molecular genetics.
13) 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
A) structural homologies.
B) vestiges.
C) homoplasies.
D) the result of shared ancestry.
14) A potential source of confusion in constructing a phylogeny tree is similarity between
organisms that is due to
A) convergent evolution.
B) adaptation.
C) shared ancestry.
D) homology.
15) A shared ancestral character is
A) a character that originated in an ancestor of the taxon.
B) shared by all mammals but not found in their ancestors.
C) an evolutionary novelty unique to a clade.
D) an outgroup character.
16) Which of the following are problematic when the goal is to construct phylogenies that
accurately reflect evolutionary history?
A) polyphyletic taxa
B) paraphyletic taxa
C) monophyletic taxa
D) polyphyletic and paraphyletic taxa
17) Which of the following is true of all horizontally oriented phylogenetic trees, in which time
advances to the right?
A) Each branch point represents a point in absolute time.
B) Organisms represented at the base of such trees are descendants of those represented at higher
levels.
C) The fewer branch points that occur between two taxa, the more divergent their DNA
sequences should be.
D) The common ancestor represented by the rightmost branch point existed more recently in
time than the common ancestors represented at branch points located to the left.
18) When using a cladistic approach to systematics, which of the following is considered most
important for classification?
A) shared primitive characters
B) analogous primitive characters
C) shared derived characters
D) the number of homoplasies
19) Cladograms (a type of phylogenetic tree) constructed from evidence from molecular
systematics are based on similarities in
A) morphology.
B) the pattern of embryological development.
C) biochemical pathways.
D) mutations to homologous genes.
20) There is some evidence that reptiles called cynodonts may have had whisker-like hairs
around their mouths. If this is true, then what can be properly said of hair?
A) It is a shared derived character of mammals, even if cynodonts continue to be classified as
reptiles.
B) It is a shared derived character of the amniote clade and not of the mammal clade.
C) It is a shared ancestral character of the amniote clade, but only if cynodonts are reclassified as
mammals.
D) It is a shared derived character of the mammals, but only if cynodonts are reclassified as
mammals.
21) According to the principle of maximum parsimony,
A) phylogenies based in DNA require the most base changes.
B) the preferred tree is the one that minimizes the amount of evolutionary change.
C) in the case of trees based on morphology, a parsimonious tree requires the most changes.
D) a large number of trees should be examined.
22) A phylogenetic tree shows that birds and crocodiles share many features. A hypothesis based
on this tree predicts that these features are present in a common ancestor. Which of these
predicted traits is supported by fossil evidence?
A) four-chambered heart
B) singing for territory
C) eggs and nests
D) singing to attract mates
23) How does a molecular clock measure time?
A) by observing that some genes and other regions of genomes appear to evolve at different rates
B) by detecting gene irregularities that result from natural selection
C) by counting the number of nucleotide substitutions over fixed period of time
D) by using few gene mutations to calibrate the clock
24) A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be
most valid for discerning the evolutionary relatedness of
A) archaeans and bacteria.
B) fungi and animals.
C) chimpanzees and humans.
D) sharks and dolphins.
25) The most important feature that permits a gene to act as a molecular clock is
A) having a large number of base pairs.
B) having a larger proportion of exonic DNA than of intronic DNA.
C) having a reliable average rate of mutation.
D) its recent origin by a gene duplication event.
E) its being acted upon by natural selection.
26) Neutral theory proposes that
A) molecular clocks are more reliable when the surrounding pH is close to 7.0.
B) most mutations of highly conserved DNA sequences should have no functional effect.
C) DNA is less susceptible to mutation when it codes for amino acid sequences whose side
groups (or R groups) have a neutral pH.
D) DNA is less susceptible to mutation when it codes for amino acid sequences whose side
groups (or R groups) have a neutral electrical charge.
E) a significant proportion of mutations are not acted upon by natural selection.
27) When it acts upon a gene, which of the following processes consequently makes that gene an
accurate molecular clock?
A) transcription
B) directional natural selection
C) mutation
D) proofreading
E) reverse transcription
28) Which of these would, if it (they) had acted upon a gene, prevent this gene from acting as a
reliable molecular clock?
A) neutral mutations
B) genetic drift
C) mutations within introns
D) natural selection
E) most substitution mutations involving an exonic codon’s third position
29) 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?
A) reptiles
B) birds
C) mammals
D) snakes
30) 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?
A) DNA coding for ribosomal RNA
B) intronic DNA belonging to a gene whose product performs a crucial function
C) paralogous DNA that has lost its function (that is, no longer codes for functional gene
product)
D) mitochondrial DNA
E) exonic DNA that codes for a noncrucial part of a polypeptide
31) 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) molecular
B) behavioral
C) nutritional
D) anatomical
E) ecological
32) Which kingdom has been replaced with two domains?
A) Plantae
B) Fungi
C) Animalia
D) Protista
E) Monera
33) What evidence allowed biologists to conclude that classification of the tree of life required a
three-domain system?
A) The validity of three domains is supported by a recent study that sequenced proteins.
B) Most of the currently known prokaryotes belong to three domains.
C) The Archaea domain consists of diverse prokaryotes that inhabit the same habitats.
D) The phylogenetic tree of the three domains of life is based on sequence data for rRNA and
other genes.
34) The kingdom Protista is obsolete because it contains members of how many other kingdoms?
A) two
B) three
C) four
D) five
20.2 Art Questions
Figure 20.1
1) Which extinct species should be the best candidate to serve as the outgroup for the clade
whose common ancestor occurs at position 2 in Figure 20.1?
A) A
B) B
C) C
D) D
E) E
2) If Figure 20.1 is an accurate depiction of relatedness, then which of the following should be
correct?
1. The entire tree is based on maximum parsimony.
2. If all species depicted here make up a taxon, this taxon is monophyletic.
3. The last common ancestor of species B and C occurred more recently than the last common
ancestor of species D and E.
4. Species A is the direct ancestor of both species B and species C.
5. The species present at position 3 is ancestral to C, D, and E.
A) 1 and 3
B) 3 and 4
C) 2, 3, and 4
D) 1, 2, and 3
Figure 20.2
3) Together, the lesser apes and great apes shared a common ancestor most recently with other
members of their
A) order.
B) class.
C) subclass.
D) subfamily.
4) Assuming chimpanzees 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) polyphyletic.
B) paraphyletic.
C) monophyletic.
D) conform with Linnaeus’s view of great ape phylogeny.