Chordates Probably Evolved from the Echinoderm-Hemichordate Assemblage

Q25: During the evolution of the vertebrates,gills changed

Q26: All chordates have<br>A)a single,dorsal,tubular,nerve cord.<br>B)a dorsal heart.<br>C)pharyngeal

Q27: The _ were jawed fishes which lived

Q28: Cephalochordates have an open circulatory system,and also

Q29: The post anal tail is seen in

Q30: In vertebrates,pharyngeal gill slits are formed by

Q31: A notochord is present at some time

Q32: The nerve cord of chordates is solid

Q34: The development of a _ life style

Q35: Vertebrate animals have<br>A)an endoskeleton.<br>B)a notochord at some