Exam 34: The Origin and Evolution of Vertebrates

The following questions refer to the description below. Terry catches a ray-finned fish from the ocean and notices that attached to its flank is an equally long,snakelike organism.The attached organism has no external segmentation,no scales,a round mouth surrounded by a sucker,and two small eyes.Terry thinks it might be a marine leech,a hagfish,or a lamprey. -Which feature excludes the organism from possibly being a leech?

Which of the following are the most abundant and diverse of the extant vertebrates?

The following questions refer to the description below. While on an intersession course in tropical ecology,Kris pulls a large,snakelike organism from a burrow (the class was granted a collecting permit).The 1-metre-long organism has smooth skin,which appears to be segmented.It has two tiny eyes that are hard to see because they seem to be covered by skin.Kris brings it back to the lab at the field station,where it is a source of puzzlement to the class.Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow). -The adaptation of the body shape of snakes has resulted in one of their lungs becoming vestigial.Another adaptation (to a fossorial lifestyle)is snakes' absence of limbs.If the "mystery organism" has also become adapted to a fossorial lifestyle,though its ancestors moved about on the surface,then which structures should one expect to find upon dissecting the organism? 1)reduced or absent pelvic and/or pectoral girdles 2)metanephridia 3)hydrostatic skeleton

Which of the following is the most inclusive (most general)group,all of whose members have foramina magna centrally positioned in the base of the cranium?

As hominins diverged from other primates,which of the following appeared first?

Having caught and handled a hagfish,what will Terry's shipmates most likely require Terry to do before returning to further fishing?