Ch 19 Flashcards
Key characteristics of all chordates?
A notochord, dorsal hollow nerve cord, pharyngeal slits, and post-anal tail
What distinguishes vertebrates from other chordates?
Backbone composed of vertebrae and a skull
Significance of jaws in vertebrate evolution?
Allowed for new feeding opportunities
What kind of skeleton do chondrichthyans have?
Flexible skeleton made primarily of cartilage
What sensory features do sharks have?
Sharp vision, keen smell, electro sensors, and a lateral line system
How are rays adapted for life on the ocean floor?
They have dorsoventrally flattened bodies & venomous spines
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What is the operculum in bony fishes?
Protective flap that covers the gills & helps them breathe without swimming
What type of skeleton do ray-finned fishes have?
Bony skeleton reinforced w/ calcium phosphate
What is the function of a swim bladder?
Helps fish maintain buoyancy
Why do amphibians require moist environments?
Their eggs & skin need moisture, & their respiratory system is primitive
What does “amphibian” mean in Greek?
“Living a double life”
Which amphibians walk with a side-to-side motion?
Salamanders
