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.
several instances of the legless condition arising independently of each other
The various taxonomic levels (namely, 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.
their inclusiveness.
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
D and F
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.
E) a hierarchical classification scheme.
phylogenies.
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) reflects the basic separation of
prokaryotes from eukaryotes.
reflects evolutionary history.
The term homoplasy is most applicable to which of the following
features?
A) the legless condition found in various lineages of
extant lizards
B) the five-digit condition of human hands and bat
wings
C) the β hemoglobin genes of mice and of humans
D) the
fur that covers Australian moles and North American moles
E) the
bones of bat forelimbs and the bones of bird forelimbs
the legless condition found in various lineages of extant lizards
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) homology.
B) homoplasy.
C)
common ancestry.
D) retro-evolution by humans.
E)
coevolution of humans and that archaean.
homoplasy.
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
bones in the bat wing and bones in the human forelimb
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.
possession of analogous structures.
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.
molecular genetics.
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.
E) molecular homologies.
homoplasies.
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?
A) Among themselves,
they should share relatively few ancestral traits, especially those
that
enabled ancestral forms to adapt to extreme
conditions.
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.
C) They should contain genes
that originated in eukaryotes that are the hosts for
numerous
species of bacteria.
D) They should currently be
undergoing a high level of horizontal gene transfer with
non-
extremophilic archaeans.
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.
Which of the following is (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 taxa and monophyletic
taxa
E) polyphyletic taxa and paraphyletic taxa
F) All of
the choices are correct.
polyphyletic taxa and monophyletic taxa
Which of the following is true of all horizontally oriented
phylogenetic trees, where 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.
E) The more branch points there are, the fewer taxa are
likely to be represented.
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.
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
E) overall phenotypic similarity
shared derived characters
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) habitat and lifestyle choices.
E)
mutations to homologous genes.
mutations to homologous genes.
There is some evidence that reptiles called cynodonts may have had
whisker-like hairs
around their mouths. If 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.
It is a shared derived character of the mammals, but only if
cynodonts are reclassified as
mammals.
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.
E) mosses and ferns.
chimpanzees and humans.
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.
having a reliable average rate of mutation.
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.
a significant proportion of mutations are not acted upon by natural selection.
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
mutation
Which of these would, if it 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
natural selection
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)
that 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 (i.e., no longer codes for functional gene
product)
D) mitochondrial DNA
E) exonic DNA that codes for a
noncrucial part of a polypeptide
that coding for ribosomal RNA
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
molecular
Which kingdom has been replaced with two domains?
A)
Plantae
B) Fungi
C) Animalia
D) Protista
E) Monera
Monera
Which eukaryotic kingdom is polyphyletic, and therefore unacceptable,
based on cladistics?
A) Plantae
B) Fungi
C)
Animalia
D) Protista
E) Monera
Protista