Deck 32: An Introduction to Animal Diversity

Question 1

Animal classification has undergone a reassessment in recent years because of:

A) Carl Linnaeus' new data
B) comparisons of DNA and rRNA among different taxa
C) new, genetically engineered species
D) developing resistance to antibiotics
E) all of the choices provided

Answer 1

comparisons of DNA and rRNA among different taxa

Question 2

The number of animal species now known is about:

A) 10 million
B) 100 million
C) 1 million
D) 15 million
E) 5 million

Answer 2

1 million

Question 3

Which of the following statements best defines the feature(s) linking all animals, but separating them from all other organisms?

A) They are terrestrial or secondarily aquatic.
B) They have digestive enzymes.
C) They are heterotrophic.
D) The nature of their small subunit rRNA gene sequences is different.
E) All of the choices provided are correct.

Answer 3

The nature of their small subunit rRNA gene sequences is different.

Question 4

Which of the following is NOT a characteristic of most animals?

A) They have Hox genes.
B) They are heterotrophic.
C) They have an extracellular matrix of proteins such as collagen.
D) They have cell walls.
E) They have a nervous system.

Question 5

The putative ancestor of animals was:

A) choanoflagellates
B) chytrids
C) gnetophytes
D) stramenopiles
E) euglenozoa

Question 6

Which of the following was NOT a major morphological criterion on which traditional classification of animals was based?

A) presence or absence of a true body cavity
B) type of symmetry
C) pattern of embryonic development
D) presence or absence of certain types of tissue
E) basic pattern of cell division

Question 7

You are given an embryo with eight cells and you carefully separate them and allow them to develop in separate containers. Each of the cells forms a complete embryo that develops normally into an adult animal. How would you categorize your animal?

A) It has indeterminate cleavage.
B) It has determinate cleavage.
C) It is a protostome.
D) It is an annelid, mollusk, or arthropod.
E) It has spiral cleavage.

Question 8

Metamerism is a characteristic feature of:

A) Annelida
B) Arthropoda
C) Chordata
D) all of the three phyla listed
E) none of the three phyla listed

Question 9

A reinterpretation of animal phylogeny (differing from morphologically based phylogeny) that was made possible by molecular techniques, was:

A) designation of the Ecdysozoa and Lophotrochozoa as clades
B) designation of the Bilateria as a monophyletic group
C) designation of annelids and arthropods as closely related
D) designation of rotifers and nematodes as closely related
E) placement of echinoderms and chordates in entirely different clades

Question 10

Traditional and molecular phylogenies disagree on which one of the following issues?

A) whether or not the Eumetazoa are monophyletic
B) whether the Bilateria and Radiata split early into separate monophyletic clades
C) whether the split between Parazoa and Eumetazoa occurred at a very early stage in animal evolution
D) whether Echinodermata and Chordata are both deuterostomes
E) whether the appearance and type of coelom is important in interpreting phylogeny

Question 11

The coelom forms in two different ways. Which of the following statements best compares those ways?

A) In schizocoelous development a solid mass of mesoderm splits to form the coelom whereas in enterocoelous development a layer of mesoderm cells forms a pocket off of the developing gut to form the coelom.
B) In enterocoelous development a solid mass of mesoderm splits to form the coelom whereas in schizocoelous development a layer of mesoderm cells forms a pocket off of the developing gut to form the coelom.
C) In enterocoelous development the coelom forms inside the mesoderm whereas in schizocoelous development the coelom forms on the outside of the mesoderm.
D) In schizocoelous development the coelom forms within the mesoderm whereas in enterocoelous development, no coelom is formed at all.
E) Schizocoelous and enterocoelous both form the coelom in identical ways, the difference merely being that the term schizocoelous is used only for deuterostomes and enterocoelous is used only for protostomes.

Question 12

The relevance of the pseudocoelom to phylogeny has been questioned. Rotifera and Nematoda both have a pseudocoelom. The molecular evidence suggests which of the following conclusions?

A) Molecular evidence confirms that rotifers and nematodes are closely related and that both participate in the same monophyletic clade.
B) Rotifers are more closely related to Lophotrochozoa than to nematodes.
C) Rotifers are more closely related to echinoderms than to nematodes.
D) Rotifers are more closely related to chordates than to nematodes.
E) Rotifers are more closely related to nematodes than to mollusks.

Question 13

The aboral side of a radially symmetrical animal is:

A) the side containing the mouth
B) the side opposite the side containing the mouth
C) its outside
D) its inside
E) All of the other choices provided are incorrect

Question 14

Metamerism is:

A) the division of the body into segments
B) the fusion of body parts
C) shedding of the skin
D) formation of the germ layers in early development
E) the first cellular division following fertilization

Question 15

If you were to discover a new species of animal that did not have body segments, but shed its exoskeleton and was a protostome, under the molecular phylogenetic scheme, you would allocate it to which of the following phyla?

A) Mollusca
B) Echinodermata
C) Nematoda
D) Platyhelminthes
E) Arthropoda

Question 16

Animals are monophyletic.

Question 17

The terms "dorsal" and "oral" are synonyms.

Question 18

Stem cells have determinate cleavage.

Question 19

Very great differences in body form can result from only small differences of gene expression.