Chapter 26 Phylogeny and the Tree of Life

Question 1

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

Answer 1

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

Question 2

2) The scientific discipline concerned with naming organisms is called
A) taxonomy.
B) cladistics.
C) binomial nomenclature.
D) systematics.
E) phylocod

Answer 2

A) taxonomy.

Question 3

3) The various taxonomic levels (viz, 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) the body sizes of the organisms assigned to each.
C) their inclusiveness.
D) the relative genome sizes of the organisms assigned to each.
E) morphological characters that are applicable to all organisms.

Answer 3

C) their inclusiveness.

Question 4

4) Which of these illustrates the correct representation of the binomial scientific name for the
African lion?
A) Panthera leo
B) panthera leo
C) Panthera leo
D) Panthera Leo
E) Panthera leo

Answer 4

E) Panthera leo

Question 5

) A phylogenetic tree that is ʺrootedʺ is one
A) that extends back to the origin of life on Earth.
B) at whose base is located the common ancestor of all taxa depicted on that tree.
C) that illustrates the rampant gene swapping that occurred early in lifeʹs history.
D) that indicates our uncertainty about the evolutionary relationships of the taxa
depicted on the tree.
E) with very few branch poin

Answer 5

B) at whose base is located the common ancestor of all taxa depicted on that tree.

Question 6

6) The correct sequence, from the most to the least comprehensive, of the taxonomic levels
listed here is
A) family, phylum, class, kingdom, order, species, and genus.
B) kingdom, phylum, class, order, family, genus, and species.
C) kingdom, phylum, order, class, family, genus, and species.
D) phylum, kingdom, order, class, species, family, and genus.
E) phylum, family, class, order, kingdom, genus, and specie

Answer 6

B) kingdom, phylum, class, order, family, genus, and species.

Question 7

7) The common housefly belongs to all of the following taxa. Assuming you had access to
textbooks or other scientific literature, knowing which of the following should provide you
with the most specific information about the common housefly?
A) order Diptera
B) family Muscidae
C) genus Musca
D) class Hexapoda
E) phylum Arthropoda

Answer 7

C) genus Musca

Question 8

8) 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) C and F
E) D and F

Answer 8

E) D and F

Question 9

9) Darwin analogized the effects of evolution as the above-ground portion of a
many-branched tree, with extant species being the tips of the twigs. The common ancestor
of two species is most analogous to which anatomical tree part?
A) a single twig that gets longer with time
B) a node where two twigs diverge
C) a twig that branches with time
D) the trunk
E) neighboring twigs attached to the same ste

Answer 9

B) a node where two twigs diverge

Question 10

10) Dozens of potato varieties exist, differing from each other in potato-tuber size, skin color,
flesh color, and shape. One might construct a classification of potatoes based on these
morphological traits. Which of these criticisms of such a classification scheme is most likely
to come from an adherent of the phylocode method of classification?
A) Flesh color, rather than skin color, is a valid trait to use for classification because it is
less susceptible to change with the age of the tuber.
B) Flower color is a better classification criterion, because below-ground tubers can be
influenced by minerals in the soil as much as by their genes.
C) A more useful classification would codify potatoes based on the texture and flavor of
their flesh, because this is what humans are concerned with.
D) The most accurate phylogenetic code is that of Linnaeus. Classify potatoes based on
Linnaean principles; not according to their color.
E) The only biologically valid classification of potato varieties is one that accurately
reflects their genetic and evolutionary relatedness

Answer 10

E) The only biologically valid classification of potato varieties is one that accurately
reflects their genetic and evolutionary relatedness

Question 11

11) The term ʺhomoplasyʺ is most applicable to which of these features?
A) the legless condition found in various types of extant lizards
B) the 5-digit condition of human hands and bat wings
C) the beta-hemoglobin genes of mice and of humans
D) the fur that covers Australian moles and North American moles
E) the basic skeletal features of dog forelimbs and cat forelimbs

Answer 11

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

Question 12

12) If, someday, an archaean cell is discovered whose SSU-rRNA sequence is more similar to
that of humans than the sequence of mouse SSU-rRNA is to that of humans, the best
explanation for this apparent discrepancy would be
A) homology.
B) homoplasy.
C) common ancestry.
D) retro-evolution by humans.
E) co-evolution of humans and that archaean

Answer 12

B) homoplasy

Question 13

13) The best classification system is that which most closely
A) unites organisms that possess similar morphologies.
B) conforms to traditional, Linnaean taxonomic practices.
C) reflects evolutionary history.
D) corroborates the classification scheme in use at the time of Charles Darwin.
E) reflects the basic separation of prokaryotes from eukaryotes

Answer 13

C) reflects evolutionary history.

Question 14

14) Which of the following pairs are the best examples of homologous structures?
A) bat wing and human hand
B) owl wing and hornet wing
C) porcupine quill and cactus spine
D) bat forelimb and bird wing
E) Australian mole and North American mol

Answer 14

A) bat wing and human hand

Question 15

15) 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.
E) possession of shared primitive characters

Answer 15

D) possession of analogous structures.

Question 16

16) In angiosperm plants, flower morphology can be very intricate. If a tree, such as a New
Mexico locust, has flowers that share many morphological intricacies with flowers of the
sweet pea vine, then the most likely explanation for these floral similarities is the same
general explanation for the similarities between the
A) dorsal fins of sharks and of dolphins.
B) reduced eyes of Australian moles and North American moles.
C) scales on moth wings and the scales of fish skin.
D) cranial bones of humans and those of chimpanzees.
E) adaptations for flight in birds and adaptations for flight in bats

Answer 16

D) cranial bones of humans and those of chimpanzees.

Question 17

17) The importance of computers and of computer software to modern cladistics is most closely
linked to advances in
A) light microscopy.
B) radiometric dating.
C) fossil discovery techniques.
D) Linnaean classification.
E) molecular genetics

Answer 17

E) molecular genetics

Question 18

18) Which mutation should least require realignment of homologous regions of a gene that is
common to several related species?
A) 3-base insertion
B) 1-base substitution
C) 4-base insertion
D) 1-base deletion
E) 3-base deletion

Answer 18

B) 1-base substitution

Question 19

19) The common ancestors of birds and mammals were very early (stem) reptiles, which almost
certainly possessed 3-chambered hearts (2 atria, 1 ventricle). Birds and mammals, however,
are alike in having 4-chambered hearts (2 atria, 2 ventricles). The 4-chambered hearts of
birds and mammals are best described as
A) structural homologies.
B) vestiges.
C) homoplasies.
D) the result of shared ancestry.
E) molecular homologies.

Answer 19

C) homoplasies.

Question 20

20) Generally, within a lineage, the largest number of shared derived characters should be
found among two organisms that are members of the same
A) kingdom.
B) class.
C) domain.
D) family.
E) order.

Answer 20

D) family.

Question 21

21) A common ancestor for both species C and E could be at position number
A) 1.
B) 2.
C) 3.
.D) 4
E) 5.

Answer 21

.D) 4