Question 1

Figure 32.1
 
-From the information provided in the figure above,how would you classify the feeding strategy of organism C?
A)suspension feeding
B)predation
C)parasitism
D)suspension feeding and predation
E)predation and parasitism

Accepted Answer

Organism C has a large mouth and a filter-feeding apparatus, which is used to filter small particles from the water. This suggests that organism C is a suspension feeder. However, organism C also has sharp teeth, which suggests that it may also be a predator. Therefore, the correct answer is D) suspension feeding and predation.

Question 2

If you think of the tube-within-a-tube body plan as a pipe with a straw inside,where would you expect to find most of the ectodermal,mesodermal,and endodermal germ layers,respectively?
A)pipe;space between pipe and straw;straw
B)straw;space between pipe and straw;pipe
C)space inside of straw;straw;space between pipe and straw
D)pipe;straw;space inside of straw

Accepted Answer

The ectoderm is the outer layer, so it would be found in the "pipe." The endoderm is the innermost layer, so it would be found in the "straw." The mesoderm is sandwiched between the ectoderm and endoderm, so it would be found in the "space between pipe and straw."

Question 3

While looking at some seawater through your microscope,you spot the egg of an unknown animal.Which of the following tests could you not use to determine whether the developing organism is a protostome or a deuterostome?
A)See whether the ectoderm forms the mature animal's skin/exoskeleton or nervous system.
B)See whether the animal exhibits spiral cleavage or radial cleavage during early development.
C)See whether the coelom is formed from a split in the mesoderm or from mesodermal pockets pinched off the gut.
D)See whether the pore formed during gastrulation becomes the mature animal's mouth or its anus.

Accepted Answer

The ectoderm forming the skin/exoskeleton or nervous system is not a distinguishing feature between protostomes and deuterostomes. Both groups have ectoderm that can form these structures.

Question 4

Figure 32.2
 
-Which morphological trait evolved more than once in animals,according to the phylogeny based on DNA sequence data found in Figure 32.2 above?
A)coelom
B)bilateral symmetry
C)segmentation
D)tissue
E)protostome development

Accepted Answer

Segmentation evolved more than once in animals, as it is found in different lineages such as annelids, arthropods, and chordates, indicating convergent evolution.

Question 5

Figure 32.1
 
-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 three organisms and observe them in detail,making the notations found in Figure 32.1.Which organism would you classify as an animal?
A)organism A
B)organism B
C)organism C

Accepted Answer

Organism C is classified as an animal because it likely exhibits characteristics typical of animals, such as mobility, heterotrophic nutrition, and possibly a lack of cell walls, which are common features distinguishing animals from plants and fungi.

Question 6

Which tissue type,or organ,is not correctly matched with its germ layer tissue?
A)nervous-mesoderm
B)muscular-mesoderm
C)stomach-endoderm
D)skin-ectoderm
E)skeletal-mesoderm

Accepted Answer

The nervous tissue is derived from the ectoderm, not the mesoderm. Therefore, option A is not correctly matched.

Question 7

Figure 32.3
Use Figure 32.3 and the following information when answering the next question.
In a review paper published in 2000,Adoutte et al.examined some animal phylogenies generated by comparing the ribosomal RNA (rRNA)of animals from many different phyla.They then integrated these independently created phylogenies into one phylogeny that best fit all the data.
Figure 32.3 compares a traditional phylogeny based on morphological characteristics (A)to the new molecular-based phylogeny described by Adoutte et al.(B).
Note that platyhelminthes,nemerteans,and entoprocts,which do not have coeloms and are classified as acoelomates in the morphological phylogeny,are reclassified as lophotrochozoans in the molecular phylogeny.Similarly,groups classified as pseudocoelomates in the morphological phylogeny are reclassified as either lophotrochozoans or ecdysozoans in the molecular phylogeny;other lophotrochozoans and ecdysozoans have coeloms.
 
-Refer to the paragraph on Adoutte et al.and Figure 32.3.What does this reclassification based on molecular data imply about the evolution of acoelomates,pseudocoelomates,and coelomates?
A)Pseudocoelomates can be seen as an intermediate stage between acoelomate and coelomate development.
B)Although acoelomates and pseudocoelomates evolved only once,coelomates evolved multiple times in different lineages.
C)Only the animals that evolved earliest are acoelomates.
D)Some pseudocoelomates and acoelomates have evolved from coelomates.

Accepted Answer

The reclassification based on molecular data suggests that some pseudocoelomates and acoelomates have evolved from coelomates, indicating a more complex evolutionary history than a simple linear progression from acoelomates to pseudocoelomates to coelomates.

Question 8

Which of the following is true of the sponges?
A)Their larvae are motile,and move via the motion of cilia.
B)They are the simplest diploblastic animals.
C)They exhibit bilateral symmetry.
D)They have a nerve net but not a CNS.
E)Their feeding cells are called choanoflagellates.

Accepted Answer

Sponges have motile larvae that move via the motion of cilia. They are not diploblastic or bilaterally symmetrical, and they do not have a nerve net or feeding cells called choanoflagellates.

Question 9

Which of the following species would you not classify as an animal?
A)sponges
B)coral
C)jellyfish
D)choanoflagellates

Accepted Answer

Choanoflagellates are unicellular eukaryotic organisms, but they are not classified as animals. They are considered the closest living relatives of animals, but they lack the specialized tissues and organs that define the animal kingdom. Sponges, coral, and jellyfish are all classified as animals.

Question 10

An organism that exhibits cephalization probably also _____.
A)is bilaterally symmetrical
B)has a hydrostatic skeleton
C)has a coelom
D)is segmented
E)is diploblastic

Accepted Answer

Cephalization is the evolutionary trend toward an organism having a distinct head region with sensory organs and a concentration of nervous tissue. Bilateral symmetry is a prerequisite for cephalization because it allows for the development of a forward-facing head region.

Question 11

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

Accepted Answer

The presence of a mouth but not an anus is a distinctive feature of protostomes, whereas deuterostomes have an anus that forms before the mouth during embryonic development.

Question 12

Why might researchers choose to use molecular data (such as ribosomal RNA sequences)rather than morphological data to study the evolutionary history of animals?
A)Molecular data can be gathered in the lab,while morphological data must be gathered in the field.
B)Sequence data can be gathered faster than morphological data,and morphological data can lead to wrong conclusions.
C)Morphological changes usually don't result from molecular changes.
D)Some phyla vary too widely in morphological characteristics to be classified accurately.

Accepted Answer

Molecular data, such as ribosomal RNA sequences, can be quickly gathered in the lab and analyzed, whereas gathering morphological data requires extensive fieldwork and can be time-consuming. Additionally, morphological characteristics can be variable within species and can lead to wrong conclusions about evolutionary relationships. Molecular data, on the other hand, reflects genetic similarities and differences, which are less likely to vary within and between species.

Question 13

Which of the following is a feature of the tube-within-a-tube body plan in most animals?
A)The outer tube consists of a hard exoskeleton.
B)The outer tube consists of digestive organs.
C)The mouth and anus form the ends of the inner tube.
D)The two "tubes" are separated by endoderm tissue.

Accepted Answer

In the tube-within-a-tube body plan, the inner tube includes the digestive tract, and the mouth and anus form its ends. This allows for a unidirectional flow of food and waste. The outer tube includes other organs and tissues, such as muscles and nerves. It is not typically a hard exoskeleton (A) or made entirely of digestive organs (B). While endoderm tissue is involved in the development of the inner tube, it is not a specific feature of the body plan itself (D).

Question 14

What do biologists cite as the primary benefit of the evolution of a coelom in animals?
A)the hydrostatic skeleton,allowing greater range of motion
B)a more efficient digestive system,in the form of a tube-within-a-tube
C)cephalization and the formation of a cerebral ganglion
D)the subsequent evolution of segmentation

Accepted Answer

The hydrostatic skeleton, allowing greater range of motion, is the primary benefit of the evolution of a coelom in animals.

Question 15

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?
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.

Accepted Answer

Endodermal cells are responsible for the development of the mosquito's gut, so inhibiting their development would likely impair gut function, leading to difficulty digesting food.

Question 16

The evolution of animal species has been prolific (the estimates go into the millions and tens of millions).To what does the text attribute much of this diversity?
A)novel reproductive strategies
B)a large variety of body plans
C)a large variety of methods for capturing and processing food
D)a complex nervous system providing the intelligence for survival in difficult times
E)the development of multiple tissue types

Accepted Answer

The text attributes much of the diversity in animal species to a large variety of methods for capturing and processing food, which is a key factor in the evolution and adaptation of species.

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?
A)It undergoes protostome development.
B)It is segmented.
C)It is triploblastic.
D)It has a coelom.
E)It sheds its external skeleton to grow.

Accepted Answer

Nematodes are known for shedding their external skeleton (cuticle) to grow, a process called ecdysis, which is not a characteristic of annelids.

Question 18

The digestive system of most animals is lined with cells through which nutrients are absorbed.What is the embryonic origin of these cells?
A)endoderm
B)ectoderm
C)mesoderm

Accepted Answer

The endoderm is the embryonic germ layer that gives rise to the lining of the digestive system in most animals.

Question 19

Which of the following is most likely to be aquatic?
A)suspension feeder
B)mass feeder
C)deposit feeder
D)fluid feeder

Accepted Answer

Suspension feeders are organisms that filter small food particles from water, which is common in aquatic environments. Mass feeders, deposit feeders, and fluid feeders do not necessarily rely on water for their feeding habits.

Question 20

The eye of most vertebrates has a flexible lens which changes shape,by the action of the ciliary muscle,depending on the distance between the lens and the object on which the animal is focusing.Which mollusk's eye is most similar to the vertebrate eye?
A)limpets
B)abalones
C)squids
D)snails
E)scallops

Accepted Answer

Squids have a similar mechanism of focusing as vertebrates, with a lens that changes shape by the contraction of the ciliary muscle. In contrast, limpets, abalones, snails, and scallops have a fixed lens or use other mechanisms to focus.

Quiz 32: An Introduction to Animals

Figure 32.1 -From the information provided in the figure above,how would you classify the feeding strategy of organism C?

If you think of the tube-within-a-tube body plan as a pipe with a straw inside,where would you expect to find most of the ectodermal,mesodermal,and endodermal germ layers,respectively?

While looking at some seawater through your microscope,you spot the egg of an unknown animal.Which of the following tests could you not use to determine whether the developing organism is a protostome or a deuterostome?

Figure 32.2 -Which morphological trait evolved more than once in animals,according to the phylogeny based on DNA sequence data found in Figure 32.2 above?

Which tissue type,or organ,is not correctly matched with its germ layer tissue?

Which of the following is true of the sponges?

Which of the following species would you not classify as an animal?

An organism that exhibits cephalization probably also _____.

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?

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 the following is a feature of the tube-within-a-tube body plan in most animals?

What do biologists cite as the primary benefit of the evolution of a coelom in animals?

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?

The evolution of animal species has been prolific (the estimates go into the millions and tens of millions) .To what does the text attribute much of this diversity?

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?

The digestive system of most animals is lined with cells through which nutrients are absorbed.What is the embryonic origin of these cells?

Which of the following is most likely to be aquatic?

The eye of most vertebrates has a flexible lens which changes shape,by the action of the ciliary muscle,depending on the distance between the lens and the object on which the animal is focusing.Which mollusk's eye is most similar to the vertebrate eye?