Question 1

What gene family is thought to be responsible for the evolution of different body plans due to their temporal and spatial expression in embryos?

Accepted Answer

A)   bHLH
B)   Hox
C)   Myb
D)   Wrky
E)   MycF) C) and E)
G) A) and E)

Question 2

In sponges, the ostium is

Accepted Answer

A)   a pore in the external wall through which water is drawn for feeding.
B)   the central cavity of the body.
C)   the pore through which the water leaves the body.
D)   the vacuole formed for food ingestion.
E)   the structure for attachment to the surface.F) A) and C)
G) A) and B) A

Question 3

Which animal phylum is NOT a member of the subkingdom Eumetazoa?

Accepted Answer

A)   Nemertea
B)   Cnidaria
C)   Porifera
D)   Platyhelminthes
E)   All these phyla belong to the EumetazoaF) D) and E)
G) All of the above

Question 4

With the exception of cnidarians and nematodes, eumetazoans can be divided into the two groups: protostomes and deuterostomes. A feature NOT used to separate these groups is the

Accepted Answer

A)   fate of the blastopore in embryo development.
B)   way the coelom forms in the embryo.
C)   way the embryonic cells divide.
D)   number of germ cell tissues.
E)   the way the mesoderm slits.F) A) and B)
G) None of the above D

Question 5

Animal phyla that show protostome development include

Accepted Answer

A)   Arthropoda, Annelida and Platyhelminthes.
B)   Platyhelminthes, Arthropoda and Echinodermata.
C)   Annelida, Mollusca and Chordata.
D)   Mollusca, Annelida, Cordata.
E)   Echinodermata, Mollusca and Platyhelminthes.F) C) and D)
G) A) and D)

Question 6

Fossil evidence about the origins of metazoans suggests that

Accepted Answer

A)   multicellularity arose about 600 million years ago.
B)   multicellularity arose independently on several different continents.
C)   early multicellular animals arose from protozoa fusing to form flat worm-like animals.
D)   metazoans evolved first in the Ediacara Hills of South Australia.
E)   All of the answers are correct.F) D) and E)
G) A) and B)

Question 7

Which statement is an accurate description of metazoans?

Accepted Answer

A)   Metazoans are unicellular.
B)   Metazoans develop from an embryo.
C)   Metazoans do not develop a zygote.
D)   Metazoans produce gametes by mitosis.
E)   Metazoans never reproduce asexually.F) B) and C)
G) A) and B)

Question 8

Ctenophores

Accepted Answer

A)   most lack nematocysts.
B)   have transparent sac-like bodies.
C)   have ciliary plates made up of fused cilia.
D)   contain a conspicuous structure, the statocyst, which is a balance organ.
E)   All of the answers are correct.F) B) and D)
G) A) and B)

Question 9

Which of the following organisms does NOT have bilateral symmetry?

Accepted Answer

A)   Box jellyfish
B)   Flat worm
C)   Slug
D)   Star fish
E)   Proboscis wormF) B) and D)
G) A) and D)

Question 10

In Platyhelminths differ from cnidarian

Accepted Answer

A)   since cnidarians have only two cell layers.
B)   because Platyhelminths have a mesoderm which leads to organ formation.
C)   because cnidarians have a skeleton of calcium carbonate.
D)   as Platyhelminths have an excretory system which opens into the archenteron adjacent to the mouth.
E)   since platyhelminths are parasites of vertebrates.F) C) and D)
G) B) and C)

Question 11

An independent, free-swimming, young medusa produced by the scyphozoan jellyfish Aurelia is called

Accepted Answer

A)   an ephyra.
B)   an actinula.
C)   a planula.
D)   a scyphistoma.
E)   a strobila.F) B) and D)
G) C) and D)

Question 12

In cnidarians, the mouth is borne on the

Accepted Answer

A)   manubrium.
B)   gastrodermis.
C)   hypostome.
D)   manubrium and gastrodermis.
E)   manubrium and hypostome.F) B) and D)
G) C) and E)

Question 13

Which animal does NOT belong to the phylum Cnidaria?

Accepted Answer

A)   Sea star
B)   Coral
C)   Sea wasp
D)   Jellyfish
E)   Sea anemoneF) A) and D)
G) A) and C) A

Question 14

The difference between monogeneans and digeneans is that monogeneans

Accepted Answer

A)   are monoecious.
B)   are endoparasites.
C)   have one host.
D)   are ectoparasites.
E)   have proglottids.F) A) and E)
G) C) and D)

Question 15

In the Porifera, which cellular layer is equivalent to the epithelium of other animals?

Accepted Answer

A)   Choanocerm
B)   Pinacoderm
C)   Mesophyl
D)   Porocylum
E)   AmoebodermF) B) and E)
G) C) and D)

Question 16

An important feature of most corals (Class Anthozoa)  not widely found among other cnidarians is

Accepted Answer

A)   a free-swimming larval stage.
B)   their ability to live in freshwater and marine habitats.
C)   a colonial habit.
D)   the presence of symbiotic algae in their tissue.
E)   sexual reproduction usually involves external fertilisation.F) A) and D)
G) None of the above

Question 17

The phylogenetic tree of animals shows that

Accepted Answer

A)   Sponges, Phylum Protozoa, are the earliest lineage.
B)   Eumetazoans are radially symmetrical.
C)   Eumetazoans diverged with one branch becoming protostomes and the other becoming deuterostomes.
D)   Protostomes and deuterostomes are distinguished by whether the blastopore becomes the mouth or the anus.
E)   The subkingdom Eumetazoa are divided into protostomes and deuterostomesF) A) and E)
G) B) and C)

Question 18

A molecular biologist mutates and silences an unknown gene in a species of turbellarian. The resulting organism appears morphologically the same as the wild-type, but is unable to adhere securely to surfaces. What might this unknown gene have been responsible for the development of?

Accepted Answer

A)   Cyclosporins
B)   Feet
C)   Lower mucilage
D)   Ventral epithelia
E)   RhabditesF) None of the above
G) All of the above

Question 19

Reproduction in flatworms occurs by

Accepted Answer

A)   cross-fertilisation.
B)   parthenogenesis.
C)   self-fertilisation.
D)   cross-fertilisation and parthenogenesis.
E)   cross-fertilisation, self-fertilisation and parthenogenesis.F) A) and C)
G) B) and C)

Question 20

The skeleton of a sponge may be composed of

Accepted Answer

A)   spongin fibres.
B)   calcium carbonate spicules.
C)   silica spicules.
D)   collagen fibres.
E)   All of answers are correct.F) B) and E)
G) A) and E)

Exam 39: Simple Animals: Sponges to Flatworms

What gene family is thought to be responsible for the evolution of different body plans due to their temporal and spatial expression in embryos?

Correct AnswerverifiedShow Answer

In sponges, the ostium is

Correct AnswerverifiedA

Which animal phylum is NOT a member of the subkingdom Eumetazoa?

Correct AnswerverifiedShow Answer

With the exception of cnidarians and nematodes, eumetazoans can be divided into the two groups: protostomes and deuterostomes. A feature NOT used to separate these groups is the

Correct AnswerverifiedD

Animal phyla that show protostome development include

Correct AnswerverifiedShow Answer

Fossil evidence about the origins of metazoans suggests that

Correct AnswerverifiedShow Answer

Which statement is an accurate description of metazoans?

Correct AnswerverifiedShow Answer

Ctenophores

Correct AnswerverifiedShow Answer

Which of the following organisms does NOT have bilateral symmetry?

Correct AnswerverifiedShow Answer

In Platyhelminths differ from cnidarian

Correct AnswerverifiedShow Answer

An independent, free-swimming, young medusa produced by the scyphozoan jellyfish Aurelia is called

Correct AnswerverifiedShow Answer

In cnidarians, the mouth is borne on the

Correct AnswerverifiedShow Answer

Which animal does NOT belong to the phylum Cnidaria?

Correct AnswerverifiedA

The difference between monogeneans and digeneans is that monogeneans

Correct AnswerverifiedShow Answer

In the Porifera, which cellular layer is equivalent to the epithelium of other animals?

Correct AnswerverifiedShow Answer

An important feature of most corals (Class Anthozoa) not widely found among other cnidarians is

Correct AnswerverifiedShow Answer

The phylogenetic tree of animals shows that

Correct AnswerverifiedShow Answer

A molecular biologist mutates and silences an unknown gene in a species of turbellarian. The resulting organism appears morphologically the same as the wild-type, but is unable to adhere securely to surfaces. What might this unknown gene have been responsible for the development of?

Correct AnswerverifiedShow Answer

Reproduction in flatworms occurs by

Correct AnswerverifiedShow Answer

The skeleton of a sponge may be composed of

Correct AnswerverifiedShow Answer

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