ONLY ANSWER IF YOU CAN HELP WITH ALL QUESTIONS!!!!!
POST LAB QUESTIONS:
1. Why is it believed that echinoderms and chordates, which are so dissimilar, are members of the same evolutionary line?
2. Describe the cloaca of a dogfish shark? Is it found in both males and females? What three systems are emptied by this structure?
3. A large surface area is a feature of both the gills and the spiral intestine of the dogfish shark. Why is this important in each case?
4. Fill in the blanks in the following sentence describing blood flow in the shark: Blood is pumped by the ___________ of the heart; it leaves the heart via the _________________ and is carried by __________________________ to the gills; the oxygenated blood is carried to the tissues via the ___________________________; deoxygenated blood is returned to the ___________________, and then goes to the ________________ which pumps it to the ____________________.
5. The madreporite is the opening of the water vascular system of an Echinoderm. It is filled with water in the starfish, but, because the madreporite of the sea cucumber is located inside the body cavity, it is actually filled with coelomic fluid in this animal. Nevertheless, the water vascular system of the starfish and the sea cucumber are similar in structure and function.
a. What is the function of the water vascular system in Echinoderms?
b. What other structure in the sea cucumber DOES use water from outside the animal? What two functions does this structure perform? Explain how this structure works.
c. What structure in the starfish performs the functions that you named above in b.
ONLY ANSWER IF YOU CAN HELP WITH ALL QUESTIONS!!!!!
POST LAB QUESTIONS:
1. Why is it believed that echinoderms and chordates, which are so dissimilar, are members of the same evolutionary line?
2. Describe the cloaca of a dogfish shark? Is it found in both males and females? What three systems are emptied by this structure?
3. A large surface area is a feature of both the gills and the spiral intestine of the dogfish shark. Why is this important in each case?
4. Fill in the blanks in the following sentence describing blood flow in the shark: Blood is pumped by the ___________ of the heart; it leaves the heart via the _________________ and is carried by __________________________ to the gills; the oxygenated blood is carried to the tissues via the ___________________________; deoxygenated blood is returned to the ___________________, and then goes to the ________________ which pumps it to the ____________________.
5. The madreporite is the opening of the water vascular system of an Echinoderm. It is filled with water in the starfish, but, because the madreporite of the sea cucumber is located inside the body cavity, it is actually filled with coelomic fluid in this animal. Nevertheless, the water vascular system of the starfish and the sea cucumber are similar in structure and function.
a. What is the function of the water vascular system in Echinoderms?
b. What other structure in the sea cucumber DOES use water from outside the animal? What two functions does this structure perform? Explain how this structure works.
c. What structure in the starfish performs the functions that you named above in b.
