Question 1

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?

Accepted Answer

A)  There is evidence of cephalization. 
B)  The animal is triploblastic. 
C)  The animal is clearly bilaterally symmetrical. 
D)  You see a mouth, but not an anus. 
A)  There is evidence of cephalization. 
B)  The animal is triploblastic. 
C)  The animal is clearly bilaterally symmetrical. 
D)  You see a mouth, but not an anus.

Question 2

Use the figure to answer the question.
 
Which of the following pairs of animals show that animals with widely different adult features can be each other's closest relatives?

Accepted Answer

A)  Annelida and Nematoda 
B)  Chordata and Echinodermata 
C)  Cnidemia and Ctenophora 
D)  Annelida and Rotifera 
A)  Annelida and Nematoda 
B)  Chordata and Echinodermata 
C)  Cnidemia and Ctenophora 
D)  Annelida and Rotifera

Question 3

The last common ancestor of all animals was probably a ________.

Accepted Answer

A)  unicellular chytrid 
B)  multicellular algae 
C)  multicellular fungus 
D)  flagellated protist 
A)  unicellular chytrid 
B)  multicellular algae 
C)  multicellular fungus 
D)  flagellated protist

Question 4

The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of

Accepted Answer

A)  a body cavity. 
B)  a complete digestive tract. 
C)  mesoderm. 
D)  tissues. 
A)  a body cavity. 
B)  a complete digestive tract. 
C)  mesoderm. 
D)  tissues.

Question 5

Use the figure to answer the question.
A: Morphological phylogeny.
 
B: Molecular phylogeny.
 
In the traditional phylogeny (A), the phylum Platyhelminthes is depicted as a sister taxon to the rest of the protostome phyla and as having diverged earlier from the lineage that led to the rest of the protostomes. In the molecular phylogeny (B), Platyhelminthes is depicted as a Lophotrochozoan phylum. What probably led to this change?

Accepted Answer

A)  Platyhelminthes ceased to be recognized as true protostomes. 
B)  The removal of the acoel flatworms (Acoela) from the Platyhelminthes allowed the remaining flatworms to be a monophyletic clade clearly tied to the Lophotrochozoa. 
C)  All Platyhelminthes must have a well-developed lophophore as their feeding apparatus. 
D)  Platyhelminthes' close genetic ties to the arthropods became clear as their Hox gene sequences were studied. 
A)  Platyhelminthes ceased to be recognized as true protostomes. 
B)  The removal of the acoel flatworms (Acoela) from the Platyhelminthes allowed the remaining flatworms to be a monophyletic clade clearly tied to the Lophotrochozoa. 
C)  All Platyhelminthes must have a well-developed lophophore as their feeding apparatus. 
D)  Platyhelminthes' close genetic ties to the arthropods became clear as their Hox gene sequences were studied.

Question 6

Based on the tree shown, which statement is false?

Accepted Answer

A)  The animal kingdom is monophyletic. 
B)  Acoelomate flatworms are more closely related to echinoderms than to annelids. 
C)  Sponges are basal animals. 
D)  Bilaterians form a clade. 
A)  The animal kingdom is monophyletic. 
B)  Acoelomate flatworms are more closely related to echinoderms than to annelids. 
C)  Sponges are basal animals. 
D)  Bilaterians form a clade.

Question 7

What do all deuterostomes have in common?

Accepted Answer

A)  Adults are bilaterally symmetrical. 
B)  Embryos have pharyngeal pouches that may or may not form gill slits. 
C)  All have a spinal column. 
D)  The pore (blastopore) formed during gastrulation becomes the anus. 
A)  Adults are bilaterally symmetrical. 
B)  Embryos have pharyngeal pouches that may or may not form gill slits. 
C)  All have a spinal column. 
D)  The pore (blastopore) formed during gastrulation becomes the anus.

Question 8

Why might researchers choose to use molecular data (such as ribosomal RNA sequences)rather than morphological data to study the evolutionary history of animals?

Accepted Answer

A)  Molecular data can be gathered in the lab, while morphological data must be gathered in the field. 
B)  Molecular data can be used to give an estimate of the time since two groups split. 
C)  Morphological changes usually do not result from molecular changes. 
D)  Some phyla vary too widely in morphological characteristics to be classified accurately. 
A)  Molecular data can be gathered in the lab, while morphological data must be gathered in the field. 
B)  Molecular data can be used to give an estimate of the time since two groups split. 
C)  Morphological changes usually do not result from molecular changes. 
D)  Some phyla vary too widely in morphological characteristics to be classified accurately.

Question 9

Which of these statements, if accurate, would support the claim that the ancestral cnidarians had bilateral symmetry?

Accepted Answer

A)  Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects. 
B)  Cnidarians have fewer Hox genes than bilaterians. 
C)  All cnidarians are acoelomate. 
D)  The presence of collar cells. 
A)  Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects. 
B)  Cnidarians have fewer Hox genes than bilaterians. 
C)  All cnidarians are acoelomate. 
D)  The presence of collar cells.

Question 10

Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion?

Accepted Answer

A)  binary fission 
B)  random segregation 
C)  gene duplication 
D)  chromosomal condensation 
A)  binary fission 
B)  random segregation 
C)  gene duplication 
D)  chromosomal condensation

Question 11

Which of the following was probably the least important factor in bringing about the Cambrian explosion?

Accepted Answer

A)  the emergence of predator-prey relationships 
B)  an increase in the concentration of atmospheric oxygen 
C)  the movement of animals onto land 
D)  the origin of Hox genes 
A)  the emergence of predator-prey relationships 
B)  an increase in the concentration of atmospheric oxygen 
C)  the movement of animals onto land 
D)  the origin of Hox genes

Question 12

Use the table to answer the following question.
\(\begin{array}{c}
\begin{array}{|l|}
\hline \
\text {Organism}\
\hline \
\
\
\text {A}\
\hline \
\
\
\
\text {B}\
\hline \
\
\
\text {C} \
\hline \
\
\
\text { D }\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Appearance}\
\hline \ 
\text {Microscopic,}\
 \text {unicellular, with a}\
\text { flagellum}\
\hline\text { Shaped like a}\ 
\text { basketball, covered }\
\text { with purple}\
 \text { filaments,}\ 
\text { multicellular }\
\hline\text {Hard and branched. }\
\text {multicellular,}\
 \text {covered in a sticky }\
\text {coating}\
\hline\
\
\text {Multicellular with }\
\text {cell walls}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Habitat/Activity}\
\hline \
\
\text {Swims around in }\
\text {freshwater pools}\
\hline \
\
\
\text {Rolls slowly across }\
\text {grassy fields}\
\hline \
\
\text {Attached to rocky }\
\text {surfaces}\
\hline \
\
\

\text {Flies across fields}\
\hline
\end{array}
\begin{array}{l|}

\hline\text {Nutrient}\
\text {Acquisition}\
\hline\text {Envelops and}\
\text {consumes other}\
\text {microscopic}\
\text {organisms}\
\hline\
\text {Thrives with access}\
\text {to only freshwater}\
\text {and sunlight}\
\hline\
\text {Traps insects in}\
\text {sticky coating and}\
\text {dissolves them}\
\hline\text {Constructs nets to}\
\text {trap flying}\
\text {organisms, and}\
\text {sucks out internal}\
\text {fluids}\
\hline
\end{array}
\begin{array}{l|}
\hline \
\text {Reproduction}\
\hline\
\
\text {Mates with others; }\
\text {young bud off}\
\hline\text {Mates with others;}\
\text { young emerge from }\
\text {hardened spherical }\
\text {structures}\
\hline\text {No mating, releases }\
\text {winged young that }\
\text {fly off and affix to}\
 \text {bare rocks}\
\hline\
\
 \text {Mates with others, }\
 \text {and disperses }\
 \text {young ballistically}\
\hline
\end{array}
\end{array}\)

As you are on the way to Tahiti for a vacation, your plane crash lands on a previously undiscovered island. You soon find that the island is teeming with unfamiliar organisms, and you, as a student of biology, decide to survey them (with the aid of the Insta-Lab Portable Laboratory you brought along in your suitcase). You select four organisms and observe them in detail, making the notations found in the figure.
Which organism would you classify as an animal?

Accepted Answer

A)  organism A 
B)  organism B 
C)  organism C 
D)  organism D 
A)  organism A 
B)  organism B 
C)  organism C 
D)  organism D

Question 13

Use the information to answer the question.
Nudibranchs, a type of predatory sea slug, can have various protuberances (that is, extensions)on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plumules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.
If nudibranch rhinophores are located at the anterior ends of these sea slugs, then they contribute to the sea slugs' ________.

Accepted Answer

A)  segmentation 
B)  lack of torsion 
C)  development of a head 
D)  identity as lophotrochozoans 
A)  segmentation 
B)  lack of torsion 
C)  development of a head 
D)  identity as lophotrochozoans

Question 14

Placing sponges as the basal metazoans on the basis of lack of tissues implies which of the following?

Accepted Answer

A)  Sponge ancestors never had tissues. 
B)  Modern-day sponges have lost the ability to form tissues. 
C)  Multicellular, modern-day choanoflagellates can form tissues. 
D)  Sponges do not have nerve cells. 
A)  Sponge ancestors never had tissues. 
B)  Modern-day sponges have lost the ability to form tissues. 
C)  Multicellular, modern-day choanoflagellates can form tissues. 
D)  Sponges do not have nerve cells.

Question 15

Arthropods invaded land about 100 million years before vertebrates. This fact most clearly implies that ________.

Accepted Answer

A)  arthropods evolved before vertebrates did 
B)  extant terrestrial arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates 
C)  vertebrates evolved from arthropods 
D)  arthropods have had more time to coevolve with land plants than have vertebrates 
A)  arthropods evolved before vertebrates did 
B)  extant terrestrial arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates 
C)  vertebrates evolved from arthropods 
D)  arthropods have had more time to coevolve with land plants than have vertebrates

Question 16

Suppose a researcher for a pest-control company developed a chemical that inhibited the development of an embryonic mosquito's endodermal cells. Which of the following would be a likely mechanism by which this pesticide works?

Accepted Answer

A)  The mosquito would develop a weakened exoskeleton that would make it vulnerable to trauma. 
B)  The mosquito would have trouble digesting food, due to impaired gut function. 
C)  The mosquito would have trouble with respiration and circulation, due to impaired muscle function. 
D)  The mosquito wouldn't be affected at all. 
A)  The mosquito would develop a weakened exoskeleton that would make it vulnerable to trauma. 
B)  The mosquito would have trouble digesting food, due to impaired gut function. 
C)  The mosquito would have trouble with respiration and circulation, due to impaired muscle function. 
D)  The mosquito wouldn't be affected at all.

Question 17

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?

Accepted Answer

A)  It is segmented. 
B)  It is triploblastic. 
C)  It has a coelom. 
D)  It sheds its external skeleton to grow. 
A)  It is segmented. 
B)  It is triploblastic. 
C)  It has a coelom. 
D)  It sheds its external skeleton to grow.

Question 18

Sponges and ctenophores have both been proposed as basal metazoans. Imagine that you wanted to provide additional evidence to help resolve this question. Which of the following projects would be the best next step?

Accepted Answer

A)  more extensive study of DNA sequences in the bilateria 
B)  ultrastructural (that is, electron microscope) comparisons of choanoflagellates and sperm cells from arthropods 
C)  measurements of molecular clocks from the Lophotrochozoa 
D)  more extensive studies of DNA sequences in both groups 
A)  more extensive study of DNA sequences in the bilateria 
B)  ultrastructural (that is, electron microscope) comparisons of choanoflagellates and sperm cells from arthropods 
C)  measurements of molecular clocks from the Lophotrochozoa 
D)  more extensive studies of DNA sequences in both groups

Question 19

In the future, phylogenetic studies should be conducted to ________.

Accepted Answer

A)  resolve the branching patterns (evolutionary history) of the Lophotrochozoa 
B)  discover the Hox genes in sponges 
C)  discover the relationships between nematodes and platyhelminthes 
D)  discover the larval stages of echinoderms 
A)  resolve the branching patterns (evolutionary history) of the Lophotrochozoa 
B)  discover the Hox genes in sponges 
C)  discover the relationships between nematodes and platyhelminthes 
D)  discover the larval stages of echinoderms

Question 20

Use the figure to answer the question.
 
Which of the following statements is supported by the phylogeny in the figure?

Accepted Answer

A)  Deuterostoma are more evolutionarily advanced than Porifera. 
B)  Traits, once they evolve, are retained in later-evolving taxonomic groups. 
C)  Animals show no evidence of convergent evolution in their traits. 
D)  Animals with extremely different adult forms can be relatively closely related. 
A)  Deuterostoma are more evolutionarily advanced than Porifera. 
B)  Traits, once they evolve, are retained in later-evolving taxonomic groups. 
C)  Animals show no evidence of convergent evolution in their traits. 
D)  Animals with extremely different adult forms can be relatively closely related.

Exam 32: An Overview of Animal Diversity

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?

Use the figure to answer the question. Which of the following pairs of animals show that animals with widely different adult features can be each other's closest relatives?

The last common ancestor of all animals was probably a ________.

The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of

Based on the tree shown, which statement is false?

What do all deuterostomes have in common?

Why might researchers choose to use molecular data (such as ribosomal RNA sequences)rather than morphological data to study the evolutionary history of animals?

Which of these statements, if accurate, would support the claim that the ancestral cnidarians had bilateral symmetry?

Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion?

Which of the following was probably the least important factor in bringing about the Cambrian explosion?

Placing sponges as the basal metazoans on the basis of lack of tissues implies which of the following?

Arthropods invaded land about 100 million years before vertebrates. This fact most clearly implies that ________.

Suppose a researcher for a pest-control company developed a chemical that inhibited the development of an embryonic mosquito's endodermal cells. Which of the following would be a likely mechanism by which this pesticide works?

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?

Sponges and ctenophores have both been proposed as basal metazoans. Imagine that you wanted to provide additional evidence to help resolve this question. Which of the following projects would be the best next step?

In the future, phylogenetic studies should be conducted to ________.

Use the figure to answer the question. Which of the following statements is supported by the phylogeny in the figure?

Evolution, the Themes of Biology, and Scientific Inquiry

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Vascular Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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