Question

1 complete summary table a - 1 in the appendix, filling in the characteristics of echinoderms in the appropriate row.
2 given that modern echinoderms and chordates look nothing alike, what factors have led zoologists to propose a close evolutionary relationship between these two phyla?
3 echinodermata is the first phylum you have examined whose members possess true endoskeletons. what are some advantages that an endoskeleton provides?
4 what is the primary function of the water vascular system?
5 what is unique about the madreporite of sea cucumbers (class holothuroidea)?
6 which of the following structures in echinoderms does not play a role in respiration (gas - exchange)? a. dermal branchiae b. respiratory trees c. coelomic fluid d. pedicellariae e. all play a role in respiration
7 match the class with the correct organism or characteristic. asterias sea lilies, feather stars sea cucumbers brittle stars soft, cylindrical body with leathery skin body contains stalk; mouth and anus on oral surface body plates fused into solid test with long, movable spines a. class crinoidea b. class ophiuroidea c. class echinoidea d. class asteroidea e. class holothuroidea

Explanation:

1. Without access to Appendix Table A - 1, cannot fill it. But characteristics of echinoderms include radial symmetry as adults, water - vascular system, etc.
2. Zoologists propose a close evolutionary relationship between echinoderms and chordates due to similarities in embryonic development like deuterostome development (blastopore becomes the anus), and similar larval forms.
3. Advantages of an endoskeleton include providing support for the body, protecting internal organs, and serving as attachment points for muscles, allowing for more efficient movement.
4. The primary function of the water vascular system in echinoderms is for locomotion, using tube feet to move, grasp objects, and for feeding.
5. In sea cucumbers (class Holothuroidea), the madreporite is often internal, located on the respiratory tree or near the esophagus, which is different from many other echinoderms where it is external.
6. Pedicellariae are small pincer - like structures in echinoderms mainly used for cleaning the body surface and defense, not for respiration. So the answer is d.
7. Asterias - d. Class Asteroidea; sea lilies, feather stars - a. Class Crinoidea; sea cucumbers - e. Class Holothuroidea; brittle stars - b. Class Ophiuroidea; soft, cylindrical body with leathery skin - e. Class Holothuroidea; body contains stalk; mouth and anus on oral surface - a. Class Crinoidea; body plates fused into solid test with long, movable spines - c. Class Echinoidea

Answer:

1. Cannot be answered without Appendix Table A - 1.
2. Similarities in embryonic development (deuterostome development and larval forms).
3. Support, protection of organs, muscle attachment for movement.
4. Locomotion (using tube feet for movement, grasping, and feeding).
5. Madreporite is often internal.
6. d. pedicellariae
7. Asterias - d. Class Asteroidea

sea lilies, feather stars - a. Class Crinoidea
sea cucumbers - e. Class Holothuroidea
brittle stars - b. Class Ophiuroidea
soft, cylindrical body with leathery skin - e. Class Holothuroidea
body contains stalk; mouth and anus on oral surface - a. Class Crinoidea
body plates fused into solid test with long, movable spines - c. Class Echinoidea