1. How is the arthropod circulatory system similar and different from the

1. How is the arthropod circulatory system similar and different from the human circulatory system? (5)
2. Why are echinoderms considered part of the Dueterostomes, despite having incredibly unique morphology? (5)
3. “All chordates are defined by the presence of an internal skeleton containing mineralized elements and pharyngeal slits at all life stages.”
What is wrong with this description and how would you change it to make it an accurate definition of chordates? (5)
4. Is a cartilaginous skeleton a homology between early gnathostomes and cyclostomes due to their shared ancestry? Explain your reasoning. (5)
5. Why are amphibians able to use positive pressure to breathe despite it being much less efficient than negative pressure. How does this relate to their lifestyle and their closer relationship with ancestral tetrapods? (5)
6. Flight in birds developed over time as a result of multiple evolutionary steps. The development of feathers, hollow bones, large flight muscles, and efficient gas exchange were all vital for flight. Describe the order in which these adaptations likely evolved and explain your reasoning. (5)