CH. 26

Question 1

how are species grouped in the linnaen system?

Answer 1

increasingly broad taxa

Question 2

what is the order of taxa from smallest to largest?

Answer 2

genera, family, order, class, phyla, kingdom, domain

Question 3

systematists depict evolutionary relationships as branching _____ ____ (many systematists propose that classification be based entirely on evolutionary relationships)

Answer 3

phylogenetic trees

Question 4

true or false: phylogenetic trees indicate ONLY patters of descent

Answer 4

true

Question 5

organisms with similar morphologies or dna sequences are (more likely or less likely) to be more closely related than organisms with very different structures and genetic sequences

Answer 5

more likely

Question 6

similarity due to shared ancestry

Answer 6

homology

Question 7

similarity due to convergent evolution

Answer 7

analogy

Question 8

a monophyletic group that includes an ancestral species and all of its descendants

Answer 8

clade

Question 9

clades can be distinguised by their ____ ____ ____

Answer 9

shared derived characters

Question 10

among phylogenies, the most parsimonious tree is the one that requires the (most or fewest) changes?

Answer 10

fewest

Question 11

homologous genes found in different species as a result of speciation

Answer 11

orthologous genes

Question 12

homologous genes within a species that result from gene duplication

Answer 12

paralogous genes

Question 13

what genes can diverge and potentially take on new functions

Answer 13

paralogous genes

Question 14

distantly related species often have many ____ genes

Answer 14

orthologous

Question 15

the small variation in gene number in organisms of varying complexity suggests that genes are ____ and may have ___ functions

Answer 15

versatile, various

Question 16

some regions of dna change at a rate consistent enough to serve as a ______ ____

Answer 16

molecular clock

Question 17

a method of estimating the date of past evolutionary events based on the amount of genetic change

Answer 17

molecular clocks

Question 18

what are the three great domains

Answer 18

bacteria, archaea, eukarya

Question 19

phylogenies based in part on rRNA genes suggest that eukaryotes are most closely related to ____, while data from some other genes suggest a closer relationship to ____

Answer 19

archaea, bacteria

Question 20

genetic analysis indicate that extensive ____ ____ ____ has occurred throughout the evolutionary history of life

Answer 20

horizontal gene transfer

Question 21

the evolutionary history of a species or group of species

Answer 21

phylogeny

Question 22

discipline focused on classifying organisms and determining their evolutionary relationshipa

Answer 22

systematics

Question 23

named taxonomic unit at any level of the linnaean hierarchy

Answer 23

taxon

Question 24

group of organisms that share an immediate common ancestor that is not shared by any other group

Answer 24

sister taxa

Question 25

lineage that diverges from all other members of its group early in the history of the group

Answer 25

basal taxon

Question 26

phylogenetic trees are intended to show patterns of ____, not phenotypic similarity

Answer 26

descent

Question 27

can we infer the ages of taxa or branch points shown in a phylogenetic tree

Answer 27

no

Question 28

we (should or should not) assume that a taxon on a phylogenetic tree evolved from the taxon next to it

Answer 28

should not

Question 29

occurs when similar environmental pressures and natural selection produce similar adaptations in organisms from different evolutionary lineages

Answer 29

convergent evolution

Question 30

similar morphology and similar dna sequences can assume that...

Answer 30

species share a recent common ancestor (only true for homologous structures)

Question 31

only ____ groups qualify as legitimate taxa in cladistics

Answer 31

monophyletic

Question 32

consists of an ancestor and some (not all) of that ancestor's descendants

Answer 32

paraphyletic grouping

Question 33

made up of ancestral taxa and all of its descendants

Answer 33

monophyletic grouping

Question 34

grouping that lacks the common ancestor of the taxa in the group

Answer 34

polyphyletic grouping

Question 35

structure that predates the branching of a particular clade from other members of that clade

Answer 35

shared ancestral characteristic