Question 1

If harbouring 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.

Accepted Answer

A) 1 and 4 
B) 2 and 4 
C) 3 and 4 
D) 2 and 5 
E) 3 and 5

Question 2

An organism that exhibits cephalization probably also ________.

Accepted Answer

A) is bilaterally symmetrical 
B) has a coelom 
C) is segmented 
D) is diploblastic

Question 3

Tp's body symmetry seems to be most like that of

Accepted Answer

A) most sponges. 
B) cnidarians. 
C) worms. 
D) tetrapods. 
E) Two of the responses above are correct.

Question 4

Use the following table to answer the questions below.
Proposed Number of Hox Genes in Various Extant and Extinct Animals
 
-All things being equal,which of these is the most parsimonious explanation for the change in the number of Hox genes from the last common ancestor of insects and vertebrates to ancestral vertebrates,as shown in the table?

Accepted Answer

A) The occurrence of seven independent duplications of individual Hox genes. 
B) The occurrence of two distinct duplications of the entire seven-gene cluster, followed by the loss of one cluster. 
C) The occurrence of a single duplication of the entire seven-gene cluster.

Question 5

When you consider the evolutionary history of animals,what are some plausible explanations for the diversification and extinction of some animal species?

Accepted Answer

A) Animal form and function changed as new adaptations evolved, resulting in new predator-prey interactions. 
B) Some animals adapted better to the atmospheric and environmental changes than others. 
C) Soft-bodied animals and small-sized animals evolve faster but also go extinct faster. 
D) Less complex animals are always first to go extinct. 
E) A and B

Question 6

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 among animals 
B) the accumulation of diverse adaptations, such as shells and different modes of locomotion 
C) the movement of animals onto land 
D) the origin of Hox genes and other genetic changes affecting the regulation of developmental genes 
E) the accumulation of sufficient atmospheric oxygen to support the more active metabolism of mobile animals

Question 7

Which of the following would you classify as something other than an animal?

Accepted Answer

A) sponges 
B) coral 
C) jellyfish 
D) choanoflagellates

Question 8

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.

Accepted Answer

A) 1 only 
B) 2 only 
C) 3 only 
D) 1 and 2 
E) 1 and 3

Question 9

Which of the following is (are)unique to animals?

Accepted Answer

A) cells that have mitochondria 
B) the structural carbohydrate, chitin 
C) nervous conduction and muscular movement 
D) heterotrophy 
E) Two of these responses are correct.

Question 10

The figure above shows a chart of the animal kingdom set up as a modified phylogenetic tree.Use the diagram to answer the following questions.
-Which two groups have members that undergo ecdysis?

Accepted Answer

A) I and II 
B) II and III 
C) III and IV 
D) III and V 
E) IV and V

Question 11

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?

Accepted Answer

A) The contrary fossil evidence will be seen as a hoax. 
B) The fossil evidence will be understood to have been incorrect because it is incomplete. 
C) The fossil record will henceforth be ignored. 
D) Phylogenies involving even the smallest bit of fossil evidence will need to be discarded. 
E) Only phylogenies based solely on fossil evidence will need to be discarded.

Question 12

In an experiment,several Tp individuals were stained different colours.The stained individuals were then passed through a strainer,disaggregated to the level of single cells,and collected into a common container of sea water.Which subsequent finding would be most surprising if the Tp individuals used in this experiment had been produced by sexual,rather than asexual,means?

Accepted Answer

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.

Question 13

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?

Accepted Answer

A) mesohyl 
B) mesoderm 
C) ectoderm 
D) endoderm 
E) mesoglea

Question 14

The most ancient branch point in animal phylogeny is that between having

Accepted Answer

A) radial or bilateral symmetry. 
B) a well-defined head or no head. 
C) diploblastic or triploblastic embryos. 
D) true tissues or no tissues. 
E) a body cavity or no body cavity.

Question 15

Placozoan evolutionary relationships to other animals are currently unclear,and different phylogenies can be created,depending on the character used to infer relatedness.Sponges have no tissues,but about 20 cell types.Tp (Trichoplax adhaerens)produces a neuropeptide almost identical to one found in cnidarians.The genome of Tp,though the smallest of any known animal,shares many features of complex eumetazoan (even human!)genomes.Use the phylogenetic trees that follow to answer the questions below.
  
I
  
II
  
III
-Which phylogeny has been created by emphasizing genomic features of placozoans?

Accepted Answer

A) I 
B) II 
C) III

Question 16

Placozoan evolutionary relationships to other animals are currently unclear,and different phylogenies can be created,depending on the character used to infer relatedness.Sponges have no tissues,but about 20 cell types.Tp (Trichoplax adhaerens)produces a neuropeptide almost identical to one found in cnidarians.The genome of Tp,though the smallest of any known animal,shares many features of complex eumetazoan (even human!)genomes.Use the phylogenetic trees that follow to answer the questions below.
  
I
  
II
  
III
-Which phylogeny has been created by emphasizing a protein found in placozoans?

Accepted Answer

A) I 
B) II 
C) III

Question 17

Use the following information to answer the questions below.
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).
-If we were to separate these eight cells and attempt to culture them individually,then what is most likely to happen?

Accepted Answer

A) All eight cells will die immediately. 
B) Each cell may continue development, but only into a nonviable embryo that lacks many parts. 
C) Each cell may develop into a full-sized, normal embryo. 
D) Each cell may develop into a smaller-than-average, but otherwise normal, embryo.

Question 18

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.

Accepted Answer

A) 1 and 2 
B) 1 and 3 
C) 2 and 4 
D) 1, 2, and 3 
E) 2, 3, and 4

Question 19

Use the following information to answer the questions below.
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 moult (though their host does),and their embryos undergo spiral cleavage.
-Which of these features is least useful in assigning the phylum Cycliophora to a clade of animals?

Accepted Answer

A) having a true coelom as a body cavity 
B) having a body symmetry that permits a U-shaped intestine 
C) having embryos with spiral cleavage 
D) lacking ecdysis (moulting)

Question 20

Protostome characteristics generally include which of the following?

Accepted Answer

A) a mouth that develops secondarily, and far away from the blastopore 
B) radial body symmetry 
C) radial cleavage 
D) determinate cleavage 
E) absence of a body cavity

Exam 32: An Overview of Animal Diversity

If harbouring 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.

An organism that exhibits cephalization probably also ________.

Tp's body symmetry seems to be most like that of

When you consider the evolutionary history of animals,what are some plausible explanations for the diversification and extinction of some animal species?

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

Which of the following would you classify as something other than an animal?

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.

Which of the following is (are) unique to animals?

The figure above shows a chart of the animal kingdom set up as a modified phylogenetic tree.Use the diagram to answer the following questions. -Which two groups have members that undergo ecdysis?

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?

The most ancient branch point in animal phylogeny is that between having

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.

Protostome characteristics generally include which of the following?