Description of the water vascular system | Homework Helpers

Question 1: Echinoderms

Describe the specialized structures and functions of echinoderms. Include in your answer:

a. a description of the water vascular system

b. a description of the aboral surface of a sea star (such as Pisaster)

c. a description of the specialized feeding structures of echinoderms (such as sea stars, urchins and sea cucumbers)

Question 2: Fish Movement

Describe the adaptations that support movement of fishes through water from the origin of swimming in chordates to the migrations of eels and salmon. Include in your answer

a. a description of the origins of swimming in chordates and the shapes of fast-swimming fishes

b. a description of gills and countercurrent exchange for obtaining oxygen

c. the synchronized development and migratory paths with ocean currents for American Eels and Pacific salmon

Question 3: Amniote Egg

Describe amniote eggs, the functions of the egg membranes and the structure and function of the calcified shells of bird eggs. Include in your answer the evolutionary transition from synapsid egg-layers to modern, placental mammals and include the adaptations that supported this transition.

Question 4: Endothermic Homeotherms

Birds and mammals originated from reptilian lineages. Modern reptiles are “cold blooded” (ectothermic poikilotherms) but birds and mammals are “warm-blooded” (endothermic homeotherms). Describe the evolutionary history of birds and mammals that led to endothermic homeothermy. Include in your essay:

a. a description of the evidence that the dinosaur ancestors of birds were warm-blooded

b. the evidence for transition to warm-bloodedness in mammals that can be detected in the fossil record (For the two subparts above, explain how each piece of evidence described indicates “warm-bloodedness”.)