Question 1

Your lab group is assigned an unknown organism to identify to the level of phylum.You have it narrowed down to either Phylum Porifera or Phylum Cnidaria.Which feature would allow you to identify the phylum of your unknown creature?

Accepted Answer

A)  presence of a central cavity
B)  presence of epidermal covering
C)  presence of one large external opening
D)  presence of pores
E)  presence of flagellated cellsF) A) and B)
G) A) and E)

Question 2

The nematode Caenorhabditis elegans is important to human medicine because it

Accepted Answer

A)  causes elephantiasis,a disease of the lymph glands that causes the legs of humans to swell.
B)  is an intestinal parasite in human digestive tracts.
C)  has programmed cell death and therefore is useful in cancer and AIDS research.
D)  is transmitted by mosquitoes and causes high fevers.E) A) and B)
F) B) and D)

Question 3

If two otherwise dissimilar organisms share similar genomic DNA,to what would you attribute the genomic similarity?

Accepted Answer

A)  The shared genes are ancient and probably no longer function within the altered physiological states of modern organisms.
B)  The shared genes have evolved a number of times and have no phylogenetic significance.
C)  The two taxa are more closely related than formerly believed.
D)  The shared genes developed early in evolution and are likely to be applicable to a wide diversity of organisms.
E)  DNA is not a reliable basis for phylogenetic decisions.F) None of the above
G) C) and D)

Question 4

When division of the zygote reaches the eight-cell stage and the planes of cleavage of the upper four cells line up with those of the bottom four cells so that two tiers of cells result,one directly above the other,the type of cleavage is called

Accepted Answer

A)  direct cleavage.
B)  spiral cleavage.
C)  indirect cleavage.
D)  protostome cleavage.
E)  radial cleavagE.F) A) and E)
G) A) and C)

Question 5

The two body forms of some Radiata is an example of alternation of generations.

Accepted Answer

A) True 
 B)False

Question 6

If a coelom had been present in a species but was then lost over time,which function would you hypothesize could be most affected?

Accepted Answer

A)  nervous
B)  muscular
C)  reproductive
D)  digestiveE) B) and D)
F) A) and B)

Question 7

What is the fate of the embryonic germ layers?

Accepted Answer

A)  The endoderm forms the gut,the ectoderm forms the epidermis and parts of the nervous system,and the mesoderm forms muscles and most internal organs.
B)  The endoderm forms the gut,the ectoderm forms the reproductive tract and endocrine system,and the mesoderm forms muscles and most internal organs.
C)  The endoderm forms the inner part of all internal organs,the mesoderm forms the middle parts,and the ectoderm forms the outer coverings.
D)  The layers are sequential structures that all disappear during development,with the endoderm appearing first and then is replaced by the mesoderm,which in turn is supplanted by the ectoderm.
E)  The endoderm is an embryonic structure that disappears early,whereas the ectoderm persists as the skin and the mesoderm as the internal organs.F) B) and E)
G) A) and B)

Question 8

What phyla of animals has the greatest number of species?

Accepted Answer

A)  Arthropoda
B)  Chordata
C)  Mollusca
D)  Annelida
E)  NematodaF) A) and E)
G) D) and E)

Question 9

What would be necessary for a sponge to survive if it had a reduced number of choanocytes?

Accepted Answer

A)  Phagocytic food gathering would have to increase.
B)  The outer protective layer would need to thicken.
C)  Intracellular digestion by choanocytes would have to increase.
D)  Spicule production by amoebocytes would have to increase.E) None of the above
F) All of the above

Question 10

What is the route of water in the water vascular system of a starfish?

Accepted Answer

A)  Water enters through the madreporite into the ring canal and from thence into the radial canals to the ampullae and finally into the tube feet.
B)  Water enters the madreporite into the radial canals and from thence into the ring canal,then the ampullae and finally into the tube feet.
C)  Water enters the madreporite into the ampullae and from thence into the ring canal,then the radial canals to the ampullae and finally into the tube feet.
D)  Water enters the ampullae and then goes to the tube feet and from thence to the radial canals,then the ring canal,and finally exits through the madreporite.
E)  Water enters the ring canal,then goes into the radial canals,and finally through the madreporite to the ampullae and tube feet.F) B) and C)
G) A) and B)

Question 11

The placement of the phylum Platyhelminthes in the phylogenetic tree differs between a morphologically based phylogeny and a molecular based phylogeny.How do scientists best differentiate the interpretation based on molecular phylogeny?

Accepted Answer

A)  Modern Platyhelminthes do not have a coelom but did originate from an ancestor that had one.
B)  The Platyhelminthes clade separated from other clades before coeloms evolved and consequently Platyhelminthes have never had a coelom.
C)  Platyhelminthes originated from ancestors with a coelom and have retained it to the present time.
D)  Platyhelminthes evolved from an ancestor without a coelom but developed one during the course of their evolution.
E)  Some Platyhelminthes have a coelom but others do not and it is difficult to conclude anything about its evolution within the cladE.F) B) and E)
G) C) and E)

Question 12

Characterize the life cycle of cnidarians.

Accepted Answer

A)  All species have both polyps and medusae.
B)  Some have only polyps,some have both polyps and medusae,and others have medusae and a reduced polyp stage.
C)  Some species have only medusae and others have both polyps and medusae.
D)  Some species have only polyps and others have both polyps and medusae.
E)  Some species have polyps and others have medusae,but no species has both.F) C) and E)
G) B) and D)

Question 13

Segmention is a characteristic feature of

Accepted Answer

A)  CnidariA.
B)  Arthropoda.
C)  Platyhelminthes.
D)  Rotifera.
E)  Nematoda.F) A) and E)
G) A) and D)

Question 14

All eumetazoans have cell junctions.

Accepted Answer

A) True 
 B)False

Question 15

The osculum of a sponge is entirely blocked by a fungal infection.Predict what will happen.

Accepted Answer

A)  Water will be unable to enter the sponge.
B)  Choanocytes will no longer be able to function.
C)  Digestion will be prevented from occurring.
D)  The flow of water out of the sponge will decrease.E) All of the above
F) A) and B)

Question 16

What was a major morphological criterion on which traditional classification of animals was based?

Accepted Answer

A)  presence or absence of a true body cavity
B)  presence or absence of specialized cells
C)  presence or absence of genetic material
D)  presence or absence of cell wall
E)  basic pattern of cell divisionF) All of the above
G) B) and E)

Question 17

A hydrostatic skeleton has no bones or cartilage.

Accepted Answer

A) True 
 B)False

Question 18

A sea star suffers from an infection that affects its ampullae.Due to the infection,the ampullae no long function.What do you predict will be the effect on the sea star.

Accepted Answer

A)  No noticeable effect will occur.
B)  The sea star will be unable to reproduce.
C)  The sea star will be unable to extend its tube feet.
D)  The sea star will be unable to store energy.E) A) and B)
F) B) and D)

Question 19

If it were found that all animals except the Parazoa had a particular set of genes,one could conclude

Accepted Answer

A)  that those genes are not useful in interpreting phylogeny.
B)  that Darwin was incorrect in his idea about descent with modification.
C)  that the Parazoa are not animals.
D)  that those genes probably are related to the embryonic formation of tissues.
E)  that those genes are related to cell wall formation.F) A) and D)
G) A) and E)

Question 20

The invertebrate group most closely related to the vertebrates is the

Accepted Answer

A)  EchinodermatA.
B)  Urochordata.
C)  Cephalochordata.
D)  Ophiouroidea.
E)  Notochordata.F) A) and E)
G) A) and B)

Exam 25: Animal Diversity: Invertebrates

The placement of the phylum Platyhelminthes in the phylogenetic tree differs between a morphologically based phylogeny and a molecular based phylogeny.How do scientists best differentiate the interpretation based on molecular phylogeny?

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What would be necessary for a sponge to survive if it had a reduced number of choanocytes?

Correct AnswerverifiedShow Answer

The two body forms of some Radiata is an example of alternation of generations.

Correct AnswerverifiedShow Answer

A sea star suffers from an infection that affects its ampullae.Due to the infection,the ampullae no long function.What do you predict will be the effect on the sea star.

Correct AnswerverifiedShow Answer

The invertebrate group most closely related to the vertebrates is the

Correct AnswerverifiedShow Answer

What is the route of water in the water vascular system of a starfish?

Correct AnswerverifiedShow Answer

What was a major morphological criterion on which traditional classification of animals was based?

Correct AnswerverifiedShow Answer

If a coelom had been present in a species but was then lost over time,which function would you hypothesize could be most affected?

Correct AnswerverifiedShow Answer

All eumetazoans have cell junctions.

Correct AnswerverifiedShow Answer

A hydrostatic skeleton has no bones or cartilage.

Correct AnswerverifiedShow Answer

Your lab group is assigned an unknown organism to identify to the level of phylum.You have it narrowed down to either Phylum Porifera or Phylum Cnidaria.Which feature would allow you to identify the phylum of your unknown creature?

Correct AnswerverifiedShow Answer

When division of the zygote reaches the eight-cell stage and the planes of cleavage of the upper four cells line up with those of the bottom four cells so that two tiers of cells result,one directly above the other,the type of cleavage is called

Correct AnswerverifiedShow Answer

What is the fate of the embryonic germ layers?

Correct AnswerverifiedShow Answer

The osculum of a sponge is entirely blocked by a fungal infection.Predict what will happen.

Correct AnswerverifiedShow Answer

Segmention is a characteristic feature of

Correct AnswerverifiedShow Answer

Characterize the life cycle of cnidarians.

Correct AnswerverifiedShow Answer

If it were found that all animals except the Parazoa had a particular set of genes,one could conclude

Correct AnswerverifiedShow Answer

The nematode Caenorhabditis elegans is important to human medicine because it

Correct AnswerverifiedShow Answer

What phyla of animals has the greatest number of species?

Correct AnswerverifiedShow Answer

If two otherwise dissimilar organisms share similar genomic DNA,to what would you attribute the genomic similarity?

Correct AnswerverifiedShow Answer

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