Kingdom Animalia Phylum Chordata All Chordates look alike

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Kingdom Animalia- Phylum Chordata

Kingdom Animalia- Phylum Chordata

All Chordates look alike at Some Point in their Development

All Chordates look alike at Some Point in their Development

Key Points Phylum is built off invertebrate traits: • Display basic traits that first

Key Points Phylum is built off invertebrate traits: • Display basic traits that first evolved in invertebrates: bilateral symmetry, cephalization (concentration of sense organs), segmentation, coelom, "gut" tube, etc. Chordate evolution has physical and behavioral specializations • Ex: forelimb of mammals specialized by natural selection Evolution led to ADAPTIVE RADIATIONS (variety of forms from a single ancestral group)

4 Major Characteristics of Chordates • Notochord, dorsal hollow nerve cord, pharyngeal gill slits,

4 Major Characteristics of Chordates • Notochord, dorsal hollow nerve cord, pharyngeal gill slits, postanal tail

The Notochord • All chordate embryos have a notochord, • Stiff flexible rod that

The Notochord • All chordate embryos have a notochord, • Stiff flexible rod that provides support • Remains throughout the life history of most invertebrate chordates; present only in the embryos of vertebrate chordates

Dorsal Hollow Nerve Cord (=Spinal Cord) • fluid-filled tube of nerve tissue that runs

Dorsal Hollow Nerve Cord (=Spinal Cord) • fluid-filled tube of nerve tissue that runs the length of the animal, above the notochord • Present in chordates throughout embryonic and adult life

Pharyngeal Gill Slits • Pairs of opening through the pharynx • Invertebrate chordates use

Pharyngeal Gill Slits • Pairs of opening through the pharynx • Invertebrate chordates use them to filter food • Fish gill sits develop into true gills • In reptiles, birds, and mammals the gill slits only occur in the embryo

Postanal Tail • The notochord, nerve cord, and the myotomes extend to the tail

Postanal Tail • The notochord, nerve cord, and the myotomes extend to the tail • Found at some time during a chordate's development

Endotherms VS Ectotherms Endotherm: -Organisms that are able to maintain a constant body temperature.

Endotherms VS Ectotherms Endotherm: -Organisms that are able to maintain a constant body temperature. -Rely on heat from internal bodily functions. Ectotherm: -Organisms that are not able to maintain a constant body temperature. -Rely on ambient heat (heat from environment)

ACTIVITY DRAW A CHORDATE AND LABEL ITS 4 CHARACTERISTIC CHORDATE STRUCTURES

ACTIVITY DRAW A CHORDATE AND LABEL ITS 4 CHARACTERISTIC CHORDATE STRUCTURES