Exam 32: An Overview of Animal Diversity

A: Morphological phylogeny. B: Molecular phylogeny. -In the traditional phylogeny (A), the phylum Platyhelminthes is depicted as a sister taxon to the rest of the protostome phyla, and as having diverged earlier from the lineage that led to the rest of the protostomes. In the molecular phylogeny (B), Platyhelminthes is depicted as a lophotrochozoan phylum. What probably led to this change?

Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran fauna?

Which of the following is descriptive of protostomes?

A: Morphological phylogeny. B: Molecular phylogeny. -What is true of the deuterostomes in the molecular phylogeny (B)that is not true in the traditional phylogeny (A)?

Whatever its ultimate cause(s), the Cambrian explosion is a prime example of

Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator-prey relationships?

The previous figure shows a chart of the animal kingdom set up as a modified phylogenetic tree. Use the diagram to answer the following questions. -Which group contains diploblastic organisms?

What do animals as diverse as corals and monkeys have in common?

At which developmental stage should one be able to first distinguish a protostome embryo from a deuterostome embryo?

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

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

Arthropods invaded land about 100 million years before vertebrates did so. This most clearly implies that

The last common ancestor of all animals was probably a

Which distinction is given more emphasis by the morphological phylogeny than by the molecular phylogeny?

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?

The previous figure 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?

In individual insects of some species, whole chromosomes that carry larval genes are eliminated from the genomes of somatic cells at the time of metamorphosis. A consequence of this occurrence is that

Table 32.1. Proposed Number of Hox Genes in Various Extant and Extinct Animals -What conclusion is apparent from the data in the table?

The blastopore is a structure that first becomes evident during

The Hox genes came to regulate each of the following in what sequence, from earliest to most recent? 1)identity and position of paired appendages in protostome embryos 2)anterior-posterior orientation of segments in protostome embryos 3)positioning of tentacles in cnidarians 4)anterior-posterior orientation in vertebrate embryos