Exam 32: An Introduction to Animal Diversity

What is the primary difference between a coelom and a hemocoel?

Use the figure to answer the question. Which of the following characteristics defines a structural distinction between Chordata and Brachiopoda?

Nine-banded armadillos give birth to four genetically identical offspring at a time. What does this fact suggest about the development of these organisms?

Trichoplax adhaerens is the only living species in the phylum Placozoa. Individuals are about 1 mm wide and only 27 μm high, and are irregularly shaped. There are four types of cells, none of which are nerve or muscle cells, and none of which have cell walls. Individual animals move using cilia, and feed on marine microbes. The body symmetry of T. adhaerens is likely to be most similar to which of the following groups of organisms?

Which of these statements, if accurate, would support the claim that the ancestral cnidarians had bilateral symmetry?

Which of the following characteristics in an organism would indicate that lacks a coelom?

Some researchers claim that sponge genomes have homeotic genes, but no Hox genes. If true, how would this impact the phylogenetic tree of animals?

Soon after the coelom begins to form, a researcher injects a dye into the coelom of a deuterostome embryo. Into which of the following structures would you expect the dye to flow?

Use the figure to answer the question. Which of the following statements is correct according to the phylogeny in the figure?

One hypothesis suggests that the Cambrian explosion was caused by the rise of predator-prey relationships. This hypothesis is best supported by an increased incidence of which of the following fossil traces?

If an organism exhibits a head with sensory structures, which of the following characteristics would it likely also exhibit?

Which of the following organisms was most likely the most recent common ancestor of all animals?

Which of the following was an early selective advantage of a coelom in animals?

Among organisms exhibiting protostome development, which morphological trait shows the most variation?

One of the characteristics unique to animals is ________.

Use the table to answer the following question. A researcher is studying animals on a previously undiscovered island, home to many unfamiliar organisms, and decides to survey them using the research equipment at hand. The researcher observes them in detail, and makes the notations shown in the table. In which of the organisms listed would you most likely find collagen?

The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of ________.

A researcher is trying to construct a molecular-based phylogeny of the entire animal kingdom. Assuming that none of the following genes are absolutely conserved, which of the following genes would be the best choice on which to base the phylogeny?

What do many organisms with deuterostome development have in common?

Use the table to answer the following question. A researcher is studying animals on a previously undiscovered island, home to many unfamiliar organisms, and decides to survey them using the research equipment at hand. The researcher observes them in detail, and makes the notations shown in the table. Which organism would you classify as an animal?