1. Explain three important embryonic componentsthat result from gastrulation, including why they are important inbilaterian animals.
2. Describe the basic difference between protostomesand deuterostomes. In which group would humans belong? Inwhich group would you expect to see identical twins, and why?
3.Explain why the notochord is especially important during theembryonic development of chordates.
4.Molecular evidence suggests that hagfish andlamprey should form sister taxa. Explain why manyphylogenies suggest that lamprey branched off after hagfish, andwould thus be more closely related to jawed vertebrates.
5.Explain why it may have been important for hagfish to havelost their backbone.
6.Explain why the life cycle of lamprey is said to beanadromous. In which part of their life cycle are theyparasites?
