1. Compare the major animal phyla in the order in which the chapter presents them, listing the new complexities seen in each group.

2. Give an example from the animal kingdom where molecular sequence information confirmed a classification based on physical resemblance.

3. In a new medical technology called preimplantation genetic diagnosis, a single cell removed from an eight-celled human embryo is tested for the presence of a disease-causing gene. If the disease isn’t present, the remaining seven-celled embryo is placed in the woman’s uterus, where it continues development. What property of early human development makes this procedure possible?

4. The Chincharro people lived on the northern coast of Chile from 5500 to 500 B.C. Many of them died at very young ages due to a number of parasitic diseases. Their preserved excrement (coprolites) and mummies contain eggs and other remains of tapeworms, roundworms, and flukes. How can a researcher tell these worms apart?

Additional Questions and Terms

1. A researcher separates the cells of a four-celled frog preembryo and regenerates four complete frogs from them. How does this information reveal whether a frog is a protostome or a deuterostome?