Bio animals essays

Bio animals essays 1.) Chordates are animals that posses a notochord, a hollow dorsal nerve cord, and pharyngeal slits at some point in its development. 2.) Vertebrates have a backbone, an endoskeleton, or skeleton on the inside of the body, a large brain in a skull, a large brain in a skull, an advanced nervous system. A complex heart and circulatory system, a special kind of outer covering, one or two pairs of appendages. 3.) The five classes of a vertebrate are the fish, amphibian, reptile, bird, and mammal classes. 4.) Lampreys are parasites. They have a circular mouth with teeth on their tongues, which they use to attach themselves to another fishs body. When they attach to the fishes(host) they scrap away at the skin with their large teeth and a strong, rasping tongue. They then suck up the tissues and the body fluids of the fish(host). They are not true fishes because they have no bones what so ever. They are the only vertebrates that do not have backbone as adults. 5.) Sharks are not true fish because they do not have scales or bones in their skeleton. The also do not have a flap of skin covering their gills as some other fishes do. Sharks just have five to seven rows of slits. 6.) Cartilage is a tough tissue that bends easily. 7.) A shark must keep swimming all the time to keep water flowing across its gills to enable it to breathe. 8.) True fishes have a bony skeleton and are covered with scales. Bony fish are what people commonly call fish. Some characteristics of true fish are skeleton of bones covered with scales, fins for swimming, gills for breathing, two-chambered heart, cold-blooded. 9.) Some fish have a swim bladder, a gas filled bag that enable them to go from shallow to deep water. 10.) Fish obtain oxygen by gulping water and passing the water over their gills. And the gills absorb the oxygen from the water, and the water is passed, by osmosis to the blood vessel. 11.) Cold-blooded mean their body tem ...