1) Both animals and fungi are heterotrophic. What distinguishes animal
heterotrophy from fungal heterotrophy is that only animals derive their
nutrition by
C)
2) The larvae of some insects are merely small versions of the adult,
whereas the larvae of other insects look completely different from
adults, eat different foods, and may live in different habitats. Which
of the following most directly favors the evolution of the latter, more
radical, kind of metamorphosis?
E)
3) Which of the following is (are) unique to animals?
A)
4) What do animals as diverse as corals and monkeys have in common?
C)
5) The Hox genes came to regulate each of the following in what sequence, from earliest to most recent?
1. identity and position of paired appendages in protostome embryos
2. anterior-posterior orientation of segments in protostome embryos
3. positioning of tentacles in cnidarians
4. anterior-posterior orientation in vertebrate embryos
C)
6) In individual insects of some species, whole chromosomes that carry
larval genes are eliminated from the genomes of somatic cells at the
time of metamorphosis. A consequence of this occurrence is that
C)
7) The last common ancestor of all animals was probably a
A)
8) Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran fauna?
D)
9) Which statement is most consistent with the hypothesis that the
Cambrian explosion was caused by the rise of predator-prey
relationships?
D)
10) Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion?
D)
11) Whatever its ultimate cause(s), the Cambrian explosion is a prime example of
B)
12) Fossil evidence indicates that the following events occurred in what sequence, from earliest to most recent?
1. Protostomes invade terrestrial environments.
2. Cambrian explosion occurs.
3. Deuterostomes invade terrestrial environments.
4. Vertebrates become top predators in the seas.
A)
13) What is the probable sequence in which the following clades of animals originated, from earliest to most recent?
1. tetrapods
2. vertebrates
3. deuterostomes
4. amniotes
5. bilaterians
B)
4) Arthropods invaded land about 100 million years before vertebrates did so. This most clearly implies that
E)
15) An adult animal that possesses bilateral symmetry is most certainly also
B)
16) Soon after the coelom begins to form, a researcher injects a dye
into the coelom of a deuterostome embryo. Initially, the dye should be
able to flow directly into the
D)
17) A researcher is trying to construct a molecular-based phylogeny of
the entire animal kingdom. Assuming that none of the following genes is
absolutely conserved, which of the following would be the best choice on
which to base the phylogeny?
E)
18) At which developmental stage should one be able to first distinguish a diploblastic embryo from a triploblastic embryo?
B)
19) At which developmental stage should one be able to first distinguish a protostome embryo from a deuterostome embryo?
E)
20) What distinguishes a coelomate animal from a pseudocoelomate animal is that coelomates
pseudocoelomates have mesenteries that hold the digestive system in
place.
D)
21) You have before you a living organism, which you examine carefully.
Which of the following should convince you that the organism is
acoelomate?
B)
22) The blastopore is a structure that first becomes evident during
D)
23) The blastopore denotes the presence of an endoderm-lined cavity in the developing embryo, a cavity that is known as the
C)
24) Which of the following is descriptive of protostomes?
A)
25) Which of the following characteristics generally applies to protostome development?
D)
26) Protostome characteristics generally include which of the following?
C)
27) The most ancient branch point in animal phylogeny is that between having
D)
28) With the current molecular-based phylogeny in mind, rank the following from most inclusive to least inclusive.
1. ecdysozoan
2. protostome
3. eumetazoan
4. triploblastic
E)
29) What does recent evidence from molecular systematics reveal about the relationship between grades and clades?
B)
30) Phylogenetic trees are best described as
D)
31) According to the evidence collected so far, the animal kingdom is
C)
32) If a multicellular animal lacks true tissues, then it can properly be included among the
B)
33) Which of the following statements concerning animal taxonomy is (are) true?
1. Animals are more closely related to plants than to fungi.
2. All animal clades based on body plan have been found to be incorrect.
3. Kingdom Animalia is monophyletic.
4. Only animals reproduce by sexual means.
5. Animals are thought to have evolved from flagellated protists similar to modern choanoflagellates.
C)
34) If the current molecular evidence regarding animal origins is
well-substantiated in the future, then what will be true of any contrary
evidence regarding the origin of animals derived from the fossil
record?
D)
35) What is true of the clade Ecdysozoa?
C)
36) Which distinction is given more emphasis by the morphological phylogeny than by the molecular phylogeny?
A)
37) The last common
ancestor of all bilaterians is thought to have had four Hox genes. Most
extant cnidarians have two Hox genes, except Nematostella (of β-catenin
fame), which has three Hox genes. On the basis of these observations,
some have proposed that the ancestral cnidarians were originally
bilateral and, in stages, lost Hox genes from their genomes. If true,
this would mean that
E)
Both Sides
38) Which of these, if true, would support the claim that the ancestral cnidarians had bilateral symmetry?
1. Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects.
2. Cnidarians have fewer Hox genes than bilaterians.
3. All extant cnidarians, including Nematostella, are diploblastic.
4. β-catenin turns out to be essential for gastrulation in all animals in which it occurs.
5. All cnidarians are acoelomate.
D)
39) Some researchers claim that sponge genomes have homeotic genes, but no Hox genes. If true, this finding would
E)
Both Sides
50) Cycliophorans
have two types of larvae. One type of larvathe Prometheus
larvadevelops into a male. The male, which lacks a digestive system,
attaches to the outside of a feeding stage (a female) and impregnates
her digestive system, which develops into a different type of larva.
What must be true of the digestive system of the feeding-stage female
while she is still a virgin?
1. At least some of its cells are haploid.
2. It consists only of highly specialized cells.
3. It is the same size as the male.
A)
Trichoplax adhaerens (Tp) is the only living species in the phylum
Placozoa. Individuals are about 1 mm wide and only 27 μm high, are
irregularly shaped, and consist of a total of about 2,000 cells, which
are diploid (2n = 12). There are four types of cells, none of which are
nerve or muscle cells, and none of which have cell walls. They move
using cilia, and any "edge" can lead. Tp feeds on marine microbes,
mostly unicellular green algae, by crawling atop the algae and trapping
it between its ventral surface and the substrate. Enzymes are then
secreted onto the algae, and the resulting nutrients are absorbed. Tp
sperm cells have never been observed, nor have embryos past the 64-cell
(blastula) stage.
51) If Tp sperm are observed by future researchers, how many chromosomes should be found in a Tp sperm nucleus?
C)
Trichoplax adhaerens (Tp) is the only living species in the phylum
Placozoa. Individuals are about 1 mm wide and only 27 μm high, are
irregularly shaped, and consist of a total of about 2,000 cells, which
are diploid (2n = 12). There are four types of cells, none of which are
nerve or muscle cells, and none of which have cell walls. They move
using cilia, and any "edge" can lead. Tp feeds on marine microbes,
mostly unicellular green algae, by crawling atop the algae and trapping
it between its ventral surface and the substrate. Enzymes are then
secreted onto the algae, and the resulting nutrients are absorbed. Tp
sperm cells have never been observed, nor have embryos past the 64-cell
(blastula) stage.
52) In how many of the following ways is Tp unlike the typical animal?
1. Tp is multicellular.
2. Tp lacks muscle and nerve cells.
3. Tp has cilia.
4. Tp has a different place where digestion of food occurs.
5. Tp lacks cell walls.
D)
Trichoplax
adhaerens (Tp) is the only living species in the phylum Placozoa.
Individuals are about 1 mm wide and only 27 μm high, are irregularly
shaped, and consist of a total of about 2,000 cells, which are diploid
(2n = 12). There are four types of cells, none of which are nerve or
muscle cells, and none of which have cell walls. They move using cilia,
and any "edge" can lead. Tp feeds on marine microbes, mostly unicellular
green algae, by crawling atop the algae and trapping it between its
ventral surface and the substrate. Enzymes are then secreted onto the
algae, and the resulting nutrients are absorbed. Tp sperm cells have
never been observed, nor have embryos past the 64-cell (blastula) stage.
53) On the basis of information in the previous paragraph, which of these should be able to be observed in Tp?
C)
Trichoplax adhaerens (Tp)
is the only living species in the phylum Placozoa. Individuals are
about 1 mm wide and only 27 μm high, are irregularly shaped, and consist
of a total of about 2,000 cells, which are diploid (2n = 12). There
are four types of cells, none of which are nerve or muscle cells, and
none of which have cell walls. They move using cilia, and any "edge" can
lead. Tp feeds on marine microbes, mostly unicellular green algae, by
crawling atop the algae and trapping it between its ventral surface and
the substrate. Enzymes are then secreted onto the algae, and the
resulting nutrients are absorbed. Tp sperm cells have never been
observed, nor have embryos past the 64-cell (blastula) stage.
54) In its native environment, a Tp cell neither gains nor loses
water. What should one expect to occur when Tp is placed into fresh
water?
B)
Trichoplax adhaerens (Tp) is the only living species in the phylum
Placozoa. Individuals are about 1 mm wide and only 27 μm high, are
irregularly shaped, and consist of a total of about 2,000 cells, which
are diploid (2n = 12). There are four types of cells, none of which are
nerve or muscle cells, and none of which have cell walls. They move
using cilia, and any "edge" can lead. Tp feeds on marine microbes,
mostly unicellular green algae, by crawling atop the algae and trapping
it between its ventral surface and the substrate. Enzymes are then
secreted onto the algae, and the resulting nutrients are absorbed. Tp
sperm cells have never been observed, nor have embryos past the 64-cell
(blastula) stage.
55) Tp's body symmetry seems to be most like that of
A)
Trichoplax adhaerens (Tp) is the only living species in the phylum
Placozoa. Individuals are about 1 mm wide and only 27 μm high, are
irregularly shaped, and consist of a total of about 2,000 cells, which
are diploid (2n = 12). There are four types of cells, none of which are
nerve or muscle cells, and none of which have cell walls. They move
using cilia, and any "edge" can lead. Tp feeds on marine microbes,
mostly unicellular green algae, by crawling atop the algae and trapping
it between its ventral surface and the substrate. Enzymes are then
secreted onto the algae, and the resulting nutrients are absorbed. Tp
sperm cells have never been observed, nor have embryos past the 64-cell
(blastula) stage.
56) In an experiment, several Tp individuals were stained
different colors. The stained individuals were then passed through a
strainer, disaggregated to the level of single cells, and collected into
a common container of seawater. Which subsequent finding would be most
surprising if the Tp individuals used in this experiment had been
produced by sexual, rather than asexual, means?
A) If all of the cells from a given individual reaggregated to form
the same individual, and if each cell had retained its original
identity, as far as cell type goes.
B) If all of the cells from a given individual reaggregated to form
the same individual, but if each cell had a different identity than it
had before disaggregation.
C) If cells from different original individuals reaggregated together to form new individual organisms.
D) If cells from different original individuals reaggregated together to form new species.
C
A student encounters an animal embryo at the eight-cell stage. The four
smaller cells that comprise one hemisphere of the embryo seem to be
rotated 45 degrees and to lie in the grooves between larger, underlying
cells (i.e., spiral cleavage).
57) This embryo may potentially develop into a(n)
A)
A student encounters an animal embryo at the eight-cell stage. The four
smaller cells that comprise one hemisphere of the embryo seem to be
rotated 45 degrees and to lie in the grooves between larger, underlying
cells (i.e., spiral cleavage).
58) If we were to separate these eight cells and attempt to culture them individually, then what is most likely to happen?
B)
The most recently discovered phylum in the animal kingdom (1995) is the
phylum Cycliophora. It includes three species of tiny organisms that
live in large numbers on the outsides of the mouthparts and appendages
of lobsters. The feeding stage permanently attaches to the lobster via
an adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
59) Which of these features is least useful in assigning the phylum Cycliophora to a clade of animals?
C)
The most recently discovered phylum in the animal kingdom (1995) is the
phylum Cycliophora. It includes three species of tiny organisms that
live in large numbers on the outsides of the mouthparts and appendages
of lobsters. The feeding stage permanently attaches to the lobster via
an adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
60) Basing your inferences on information in the previous paragraph, to which clade(s) should cycliophorans belong?
1. Eumetazoa
2. Deuterostomia
3. Bilateria
4. Ecdysozoa
5. Lophotrochozoa
C)
The most recently discovered phylum in the animal kingdom (1995) is the
phylum Cycliophora. It includes three species of tiny organisms that
live in large numbers on the outsides of the mouthparts and appendages
of lobsters. The feeding stage permanently attaches to the lobster via
an adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
61) If harboring large populations of cycliophorans neither
helps nor harms their lobster hosts, then cycliophorans can be properly
considered to be
1. parasites.
2. mutualists.
3. commensals.
4. symbionts.
5. endosymbionts.
A)
The most recently discovered phylum in the animal kingdom (1995) is the
phylum Cycliophora. It includes three species of tiny organisms that
live in large numbers on the outsides of the mouthparts and appendages
of lobsters. The feeding stage permanently attaches to the lobster via
an adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
62) On the basis of the cleavage pattern of cycliophoran embryos, which of these should be true?
D)
The most recently discovered phylum in the animal kingdom (1995) is the
phylum Cycliophora. It includes three species of tiny organisms that
live in large numbers on the outsides of the mouthparts and appendages
of lobsters. The feeding stage permanently attaches to the lobster via
an adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
63) Using similarities in embryonic development, body symmetry,
and other anatomical features to assign an organism to a clade involves
1. cladistics based on body plan.
2. molecular-based phylogeny.
3. morphology-based phylogeny.
C)
The most recently discovered phylum in the animal kingdom (1995) is the
phylum Cycliophora. It includes three species of tiny organisms that
live in large numbers on the outsides of the mouthparts and appendages
of lobsters. The feeding stage permanently attaches to the lobster via
an adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
64) Which of these, if discovered among cycliophorans, would
cause the most confusion concerning our current understanding of
cycliophoran taxonomy?
D)
The most recently discovered phylum in the animal kingdom (1995) is the
phylum Cycliophora. It includes three species of tiny organisms that
live in large numbers on the outsides of the mouthparts and appendages
of lobsters. The feeding stage permanently attaches to the lobster via
an adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
65) What is true of the feeding stage of cycliophorans?
1. It is chemoheterotrophic.
2. It is sessile.
3. It captures food in a manner similar to that of animals with lophophores.
4. It has radial symmetry.
D)
he most recently
discovered phylum in the animal kingdom (1995) is the phylum
Cycliophora. It includes three species of tiny organisms that live in
large numbers on the outsides of the mouthparts and appendages of
lobsters. The feeding stage permanently attaches to the lobster via an
adhesive disk, and collects scraps of food from its host's feeding by
capturing the scraps in a current created by a ring of cilia. The body
is sac-like and has a U-shaped intestine that brings the anus close to
the mouth. Cycliophorans are eucoelomate, do not molt (though their host
does), and their embryos undergo spiral cleavage.
66) Cycliophorans have two types of larvae. One type of larva is
produced when the digestive system of a female is impregnated by a
male. The digestive system then collapses and develops into a larva,
which swims away in search of a new host after the surrounding female
dies. Which is the embryonic tissue that is apparently most important in
forming this type of larva?
E)
70) Among the characteristics unique to animals is
D)
71) The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of
D)
72) Acoelomates are characterized by
D)
73) Which of the following was probably the least important factor in bringing about the Cambrian explosion?