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BIOLOGY 120 LAB CERRITOS COLLEGEExercise 13 L. L. Harris

THE ECHINODERMS AND CHORDATES(rev. 11.17.03)

I. THE PHYLUM ECHINODERMATA

A. INTRODUCTION

Name literally means "spiny skin"Bilateral larvae; radial symmetry as adult [most have a 5-fold radial symmetry]

Examples: _____________________________________________________________________

B. ECHINODERM CHARACTERISTICS – THE SEA STAR AS THE PHYLUM REPRESENTATIVE:

True coelom but no obvious segmentation. Flexible endoskeleton (called a "test")

Skin is equipped with gills and small pinchers to keep the gills free of debris De-centralized nervous system – "ring of ganglia" with nerve cords with sensory antenna and a photoreceptor at the tip of each arm; advantage to this is that each arm can serve as a “head”! Dioecious with external fertilization

Locomote & Feed via water-vascular system w/ tube feet

Digestion is described as being "external" – __________________________________________

_______________________________________________________________________

Capable of regeneration - "Oysterman Story" – _______________________________________ ______________________________________________________________________________

______________________________________________________________________________

C. ADDITIONAL VOCABULARY

DEUTEROSTOMES – ___________________________________________________________

______________________________________________________________________________

PROTOSTOMES – ______________________________________________________________

______________________________________________________________________________

II. PHYLUM CHORDATA

Distinguishing Characteristics:

Dorsal Hollow Nerve Cord - _______________________________________________________

Notochord - ____________________________________________________________________

Pharyngeal Clefts [Aka Gill Slits] - __________________________________________________

Post-Anal Tail – _________________________________________________________________

A. SUBPHYLUM UROCHORDATA

Common Name: Tunicates [aka "Sea Squirts"] Only the larval form shows the 4 characters

They are sessile as adults (see manual picture)

B. SUBPHYLA CEPHALOCHORDATA

Amphioxus (AKA Lancelet) All 4 chordate characters are retained by adult Locomotion via myotomes attached to notochord

C. SUBPHYLUM VERTEBRATA

FATES OF THE FOUR CHORDATE CHARACTERISTICS IN Homo sapiens:

DHNC becomes the _____________________________________________________________

Notochord becomes the __________________________________________________________

Gill Arches become ______________________________________________________________

Post-Anal Tail becomes __________________________________________________________

7 VERTEBRATE CLASSES ARE EXTANT: (Extant means that they are not extinct!)

Class Agnatha - __________________________________________________________________

______________________________________________________________________________

Class Chondrichthyes - ____________________________________________________________

______________________________________________________________________________

Class Osteichthyes - ______________________________________________________________

______________________________________________________________________________

Class Amphibia - _________________________________________________________________

______________________________________________________________________________

Class Reptilia - ___________________________________________________________________

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Amphioxus:

______________________________________________________________________________

Class Aves - _____________________________________________________________________

______________________________________________________________________________

Class Mammalia - ________________________________________________________________

______________________________________________________________________________

MAMMALIAN SUBCLASSES: (BASED ON REPRODUCTIVE MODES)

Monotremes - _________________________________________________________________

Marsupials - ___________________________________________________________________

Placentals - ___________________________________________________________________

II. FURTHER VERTEBRATE CONSIDERATIONS

1. ENDOTHERMIC vs. ECTOTHERMIC

Birds & Mammals Are Endotherms. Members of other classes are Ectotherms.

Ectothermic - _______________________________________________________________

Endothermic - ______________________________________________________________

2. EARLY DEVELOPMENT OF VERTEBRATE YOUNG Oviparous - ____________________________________________________________________

Oviviviparous - _________________________________________________________________

Viviparous - ____________________________________________________________________

3. THE VERTEBRATE TETRAPOD CLASSES [Amphibians - Reptiles - Aves - Mammals]

Tetrapods = 4-limbed. Includes even those animals that have "lost" their limbs. (snakes, that is!)

III. VOCABULARY:

Myotomes - ________________________________________________________________________

Claspers - _________________________________________________________________________

Denticles - _________________________________________________________________________

Swim Bladder - _____________________________________________________________________

Operculum - _______________________________________________________________________

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Amniotic Egg - ______________________________________________________________________

Cloaca - ___________________________________________________________________________

Archeopteryx - ______________________________________________________________________

Mammary Glands - __________________________________________________________________

Endothermic - ______________________________________________________________________

Ectothermic - _______________________________________________________________________

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