front 1 2) Which of the following is (are) unique to animals? C) heterotrophy | back 1 B |
front 2 8) Use the information to answer the question. Trichoplax adhaerens 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. Individual animals move using cilia, and any "edge" can lead. T. adhaerens 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. T. adhaerens sperm cells have never been observed, nor have embryos past the 64-cell (blastula) stage. Which of the following T. adhaerens traits is different from all other known animals? A) T. adhaerens is multicellular. D) T. adhaerens lacks cell walls. | back 2 B |
front 3 7) Both animals and fungi are heterotrophic. What distinguishes
animal heterotrophy from fungal heterotrophy is that most animals
derive their nutrition by ________. C) consuming living, rather than dead, prey | back 3 B |
front 4 10) 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
________. | back 4 A |
front 5 11) The fact that choanoflagellates and collar cells of sponges
resemble each other supports the inference that ________. C) choanoflagellates and sponges are sister groups | back 5 C |
front 6 12) Which of the following would you classify as something other than an animal? A) sponge D) choanoflagellate | back 6 D |
front 7 13) The evolution of animal species has been prolific (current
estimates of species numbers reach into the tens of millions). Much of
this diversity is a result of the evolution of novel ways to
________. B) arrange cells into tissues | back 7 C |
front 8 14) The last common ancestor of all animals was probably a ________. A) unicellular chytrid D) flagellated protist | back 8 D |
front 9 19) Arthropods invaded land about 100 million years before
vertebrates. This fact most clearly implies that ________. C) vertebrates evolved from arthropods | back 9 D |
front 10 22) Which tissue type or organ is not correctly matched with its germ layer tissue? A) nervous—mesoderm D) skin—ectoderm | back 10 A |
front 11 23) While looking at some seawater through your microscope, you spot
the egg of an unknown animal. Which of the following tests could you
use to determine whether the developing organism is a protostome or a
deuterostome? See whether the embryo ________. B) exhibits spiral cleavage or radial cleavage C) develops a blastopore | back 11 B |
front 12 24) In examining an unknown animal species during its embryonic
development, how can you be sure what you are looking at is a
protostome and not a deuterostome? C) The animal is clearly bilaterally symmetrical. D) You see a mouth, but not an anus. | back 12 D |
front 13 25) Which of the following is a feature of the
"tube-within-a-tube" body plan in most animal phyla? C) The mouth and anus form the ends of the inner tube. | back 13 C |
front 14 27) Among protostomes, which morphological trait has shown the most variation? A) type of symmetry (bilateral versus radial versus none) D) type of development (protostome versus deuterostome) | back 14 B |
front 15 28) What do all deuterostomes have in common? | back 15 D |
front 16 32) A student encounters an animal embryo at the eight-cell stage.
The four smaller cells that comprise 1 hemisphere of the embryo seem
to be rotated 45° and to lie in the grooves between larger, underlying
cells. This embryo may potentially develop into a(n) ________. B) earthworm | back 16 B |
front 17 35) The protostome developmental sequence arose just once in
evolutionary history, resulting in two main subgroups—Lophotrochozoa
and Ecdysozoa. What does this finding suggest? C) Division of these two groups occurred after the protostome
developmental sequence appeared. | back 17 C |
front 18 36) Which of these statements, if accurate, would support the claim
that the ancestral cnidarians had bilateral symmetry? C) All cnidarians are acoelomate. | back 18 A |
front 19 41) What is the probable sequence in which the following animal
clades originated, from earliest to most recent? C) deuterostomes, bilaterians, amniotes, vertebrates, tetrapods D) deuterostomes, bilaterians, vertebrates, tetrapods, amniotes | back 19 A |
front 20 42) The most ancient branch point in animal phylogeny is the characteristic of having ________. A) radial or bilateral symmetry D) a body cavity or no body cavity | back 20 C |
front 21 43) When a scientist describes the "body plan" of a phylum, he or she is implying that ________. A) organisms direct their own evolution in order to maximize their
success D) mutations have arisen that allow only some shapes to be produced | back 21 C |
front 22 44) Which of the following statements comparing symmetry in sessile
and swimming animals is most probable? C) Bilateral symmetry allowed animals to evolve nerves. D) Bilaterally symmetric animals can be streamlined for swimming, but radially symmetric animals cannot. | back 22 D |
front 23 46) Nine-banded armadillos give birth to four offspring at a time. An
amazing fact about these offspring is that they are genetically
identical to each other. This fact suggests ________. C) the first cell division of the fertilized egg is perpendicular to the vertical axis of the egg D) the species is pseudocoelomate | back 23 B |
front 24 47) You find a new species of worm and want to classify it. Which of
the following lines of evidence would allow you to classify the worm
as a nematode and not an annelid? C) It has a coelom. | back 24 D |
front 25 48) The common ancestor of the protostomes had a coelom. What does this suggest? A) All lophotrochozoans have a coelom. D) The body cavity evolved before the lophophore. | back 25 D |
front 26 1) One of the characteristics unique to animals is A) gastrulation. D) flagellated sperm. | back 26 A |
front 27 2) The distinction between sponges and other animal phyla is based
mainly on the absence versus the presence of C) mesoderm. | back 27 D |
front 28 63) Placing sponges as the basal metazoans on the basis of lack of
tissues implies which of the following? C) Multicellular, modern-day choanoflagellates can form tissues. D) Sponges do not have nerve cells. | back 28 A |
front 29 18) The presence of a lophophore in a newly discovered species would
suggest that the species ________. C) is motile | back 29 D |
front 30 9) You find what you believe is a new species of animal. Which of the following characteristics would enable you to argue that it is more closely related to a flatworm than it is to a roundworm? A) It is a suspension feeder. C) It is shaped like a worm. | back 30 B |
front 31 21) Which of the following organisms would you expect to have the
largest surface-area-to- volume ratio? Assume that all of the
following are the same total length. C) an arthropod | back 31 D |
front 32 23) While sampling marine plankton in a lab, a student encounters large numbers of fertilized eggs. The student rears some of the eggs in the laboratory for further study and finds that the blastopore becomes the mouth. The embryo develops into a trochophore larva and eventually has a true coelom. These eggs probably belonged to a(n) ________. A) echinoderm | back 32 B |
front 33 35) Which characteristic is shared by cnidarians and flatworms? A)
dorsoventrally flattened bodies D) a distinct head | back 33 C |
front 34 36) If a lung were to be found in a mollusc, where would it be located? A) mantle cavity D) excurrent siphon | back 34 A |
front 35 38) Molecular studies have changed many of the phylogenetic
relationships previously identified by morphological studies. An
example of such a change is ________. C) Brachiopoda | back 35 A |
front 36 40) Large animals need specialized organs for gas exchange because ________. A) they require more oxygen per unit of volume D) they collect more energy and therefore have more energy to allocate to specialized tissues | back 36 C |
front 37 44) Which of the following changes would lead to an increase in surface-area-to-volume ratios? A) thickening of the body of earthworms D) reducing the branching of the mesoderm tissues of sponges | back 37 B |
front 38 47) Nematodes and arthropods both ________. B) are parasites | back 38 C |
front 39 51) All insects ________. D) have jointed appendages and spicules | back 39 C |
front 40 57) The heartworms that can accumulate within the hearts of dogs and
other mammals have a pseudocoelom, an alimentary canal, and an outer
covering that is occasionally shed. To which phylum does the heartworm
belong? B) Arthropoda | back 40 C |
front 41 58) A terrestrial animal species is discovered with the following
larval characteristics: exoskeleton, system of tubes for gas exchange,
and modified segmentation. A knowledgeable zoologist should predict
that the adults of this species would also feature ________. | back 41 D |
front 42 59) In a tide pool, a student encounters an organism with a hard outer covering that contains much calcium carbonate, an open circulatory system, and gills. The organism could potentially be a crab, a shrimp, a barnacle, or a bivalve. The presence of which of the following structures would allow for the most certain identification of the organism? A) a mantle | back 42 A |
front 43 72) The water vascular system of echinoderms ________. D) is analogous to the gastrovascular cavity of flatworms | back 43 B |
front 44 73) Which of the following combinations correctly matches a phylum to its description? A) Echinodermata—bilateral symmetry as a larva, water vascular
system D) Platyhelminthes—radial symmetry, polyp and medusa body forms | back 44 A |
front 45 74) Which of the following animal groups is entirely aquatic? A) Mollusca D) Nematoda | back 45 C |