Echinodermata And Chordata

Front 1

Describe the body plan of the phylum Chordata

Back 1

Triploblastic, bilateral symmetry, complete gut, eucoelomate (enterocoelous), organ system grade of organization, metamerism, cephalization

Front 2

the five characteristic features of chordates

Back 2

notochord, dorsal hollow nerve chord, pharyngeal pouches and slits, endostyle (thyroid gland), postanal tail

Front 3

Describe the body plan of phylum Echinodermata.

Back 3

Pentaradial symmetry, triploblastic, coelomate, complete gut, deurdstomes, diffuse nervous system

Front 4

1What is pentaradial symmetry and how does it manifest in echinoderms

Back 4

five-fold circular pattern; any one-fifth "pie slice" of an echinoderm should have all of the same structures as any other

Front 5

Most adult echinoderms are an exception to this generalization – they are free-moving yet radially symmetrical. From an evolutionary standpoint, how/why did this happen?

Back 5

Many zoologists believe that early echinoderms were sessile and evolved radiality as an adaptation to sessile existence. Radiality is of value to animals whose environment meets them on all sides equally. Therefore the body plan of present day echinoderms seems to have derived from one that was attached to the sea floor, had radial symmetry and radiating grooves for food gathering, and an upward facing oral side.

Front 6

Describe the endoskeleton of echinoderms. Why is it considered an endoskeleton rather than an exoskeleton.

Back 6

The endoskeleton of echinoderms is made of small calcareous plates (OSSICLES) bound together with connective tissue. Spines project from these plates. Endoskeleton because it is located underneath the epidermis

Front 7

What are pedicellariae (ped-a-cell-air-ee-ee) and what is their function?

Back 7

Modified movable spines that keep body surface free of debris, protect papulae (skin gills), and can aid in food capture. (In some sea urchins, these bear venom glands and their toxin paralyzes small prey)

Front 8

Describe the role of the water vascular system in each of the following: locomotion, food gathering, and respiration. Be specific.

Back 8

:set of canals and specialized tube feet that, with the dermal ossicles, form a special hydraulic system. Echinoderms move by alternately contracting muscles that force water into the tube feet, causing them to extend and push against the ground, then relaxing to allow the feet to retract

Front 9

How do adult echinoderms respire?

Back 9

no specialized organs for respiration or excretion.
skin gills & tube feet function as respiratory surfaces
gases diffuse from these structures into coelomic fluid.

Front 10

Which of the five chordate features are present in adult humans? Which ones are missing, and what happened to them?

Back 10

Notochord was replaced my vertebrae. Anterior end of nerve cord becomes brains. Pharyngeal slits don’t open, but the grooves are there. thyroid gland is present. postanal tail is evident in humans (coccyx).

Front 11

What is the function of the pharynx in (a) amphioxus and tunicates, (b) modern fishes, (c) tetrapods?

Back 11

a. strainer for food gathering
b. still serves in feeding (suction feeding)
c. puches give rise to Eustachian tubes, middle ear cavity, tonsils and parathyroid glands

Front 12

the function of the endostyle in protochordates?

Back 12

Secretes mucus that traps small food particles brought into the pharyngeal cavity

Front 13

Describe the lifestyle of adult tunicates

Back 13

Sea squirts are mostly sessile, lose most chordate features. Are filter feeders

Front 14

Describe the lifestyle of amphioxus

Back 14

Water enters the mouth (driven by cilia) in the buccal cavity and pharynx
Water passes through pharyngeal slits where food is trapped in mucus secreted by the endostyle