BIO229 LECTURE 9 EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED GRADED A++

BIO229 LECTURE 9 EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED GRADED A++ Leave the first rating Practice questions for this set Terms in this set (37) why are teeth and jaws important to evolutionary biologists? - Often very characteristic - Hard structures so well preserved in fossil record what did Haeckal realise that was crucial to the understanding of the origin of the jaw? He noted that between cyclostomes and gnathostomes is not Jaws but the presence of a single nostril or a double nostril. this difference is associated w/ the position of the nasal sacs relative to the adenohypophysis describe the primitive teeth of agnathans composed of bone, dentine and enamel. Form from interaction between ectoderm and mesoderm when did jaws evolve after agnathans separated 180Ma before the tetrapods emerged. Clade:Gnathostomes describe the pharyngeal stage of jaws seen in embryonic development in all vertebrates. six pharngeal arches associated with six pouches. the mesoderm associated with each arch has its own specified cranial nerve and blood supply from the aortic arches describe the origin hypothesis of ancestral jaw condition the mandibular arches forming a functional gill arch and the first pouch forming a complete gill slit