NAME:_________________________ DATE:_________________________
Chordata
1. Major Characteristics
All chordates have the following features at some point in their life (indicating common ancestry). In the
case of humans and many other vertebrates, these features may only be present in the embryo:

_____________________________ ______________________ - a series of openings that
connect the inside of the throat to the outside of the "neck" (opening between pharynx and
outside). Primitive chordates slits are used to _____________________ food particles from
water, in fishes slits were used as _______________________. Land living chordates they are
present in _____________________________ stages only and later close up.

Hollow _______________________ nerve cord - a bundle of nerve fibers which runs down the
"back". It connects the brain with the lateral muscles and other organs. Note that in most
invertebrates, nerve cords had ran along ventral surface

__________________________________ - cartilaginous rod running underneath, and
supporting, the nerve cord. It runs the length of the animal. In animals without bones the
muscles work against the notochord to move the animal. In vertebrates the notochords are
replaced and surrounded by vertebrae or backbones

_______________________________ - an extension of the body past the anal opening. Feature
is lost in many chordates such as frogs and people
2. General Characteristics
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Closed circulatory system, and most, but not all, chordates have a _________________. The
blood of most chordates contains the oxygen-carrying molecule _______________________.
The muscles of the body are segmented into blocks called ______________________________.
Like their relatives the _____________________________, chordates are deuterostomes, which
means in early embryonic development, the anus forms before the _____________________.
NAME:_________________________ DATE:_________________________
3. Subphylums of Chordata
Phylum Chordata includes
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Vertebrates
o __________________________
o _________________, amphibians, reptiles, __________________ and mammals
Tunicates
o Small marine filter feeders
o Have a special body covering called a _____________________.
o Larvae has a notochord and dorsal nerve cord
o As mature undergo metamorphosis and become sessile adults that grow into
colonies attached to a solid surface
o Adult tunicates __________________ feed and breathe at the same time
through gill slits in the pharynx
Lancelets
o Small jawless fishlike creatures
o Live in sandy bottom of shallow tropical oceans
o Adults have a definite head, mouth with many ____________ slits for filter
feeding
o Primitive heart pumps blood through vessels in a closed circulatory system
o No appendages, move by bending their bodies