chapter 22

Question 1

a phylogenetic tree is a:

A. hypothesis about the evolutionary history of species.
B. guess about the evolutionary history of species.
C. factual representation of the evolutionary history of species.
D. detailed timeline of a species’ evolutionary history.
E. None of the other answer options is correct.

Answer 1

the answer is A

Question 2

what does a node represent?

Answer 2

it represents their last common ancestor

Question 3

what are sister groups in a phylogenetic tree?

Answer 3

they are two groups that are more closely related to each other than either is to anything else on the tree.

Question 4

which of the statements is always true about sister taxa on a phylogenetic tree?
A. sister taxa are always the result of speciation events that result in two new genera.
B. sister taxa always share a most recent common ancestor that is not shared with any other taxon on the phylogeny.
C. sister taxa are always the result of the most recent divergence event represented on a phylogeny.
D. sister taxa are always defined by shared ancestral characteristics that have been modified in all other taxa in the phylogeny.

Answer 4

the answer is B.

Question 5

what is a monophyletic group?

Answer 5

includes a common ancestor and all of its descendants

Question 6

what is a paraphyletic group?

Answer 6

includes a common ancestor and some, but not all of its descendants

Question 7

what is a polyphyletic group?

Answer 7

does not include the common ancestor

Question 8

what are the three main domains?

Answer 8

eukarya, bacteria, and archaea

Question 9

which phylogenetic group includes all descendants of a common ancestor and only the descendants of that ancestor?
A. monophyletic
B. paraphyletic
C. polyphyletic
D. genus

Answer 9

the answer is A. monophyletic

Question 10

note : characters are used to construct phylogenies.
when constructing a phylogenetic tree, morphological, physiological, or molecular features can be used to determine similarity between species.

Answer 10

!

Question 11

analogous characters are

Answer 11

those that arose because of similar selective environments
example : wings in both birds and bats do not reflect descent from a common winged ancestor; instead, wings evolved independently in the two groups.

Question 12

homologous characters are present

Answer 12

in groups that descended from a common ancestor

Question 13

define a clade?

Answer 13

an ancestor and all its descendents

Question 14

synapomorphies are shared…

Answer 14

derived characters that arose from a common ancestor

Question 15

complete the following statement: characters that are similar because of descent from a common ancestor are:

A. homologous.
B. analogous.
C. examples of convergent evolution.
D. synapomorphies.

Answer 15

the answer is A. homologous

Question 16

using distance-based methods to construct a phylogenetic tree requires:
A. at least 10% of the genome sequence for each taxon
B. a large number of DNA differences between all taxa
C. many independent mutations in each taxon
D. a constant evolutionary rate of change in the DNA of the taxa

Answer 16

the answer is D.

Question 17

the development of wings on a moth and a bird are [blank] because they developed independently as adaptations to perform the common function of flying.
A. homologous
B. identical
C. related
D. analogous

Answer 17

the answer is D. analogous

Question 18

why is the fossil record not a complete catalog of biological history?
A. the process of fossilization often destroys anatomical features of the organisms being preserved
B. fossilization destroys the structure of DNA
C. fossils only preserve organisms for about 10 million years; older organisms are destroyed by geological processes
D. only animals, not plants, are fossilized
E. not all organisms fossilize with equal probability

Answer 18

the answer is E.