Biology Kingdoms Sixth section for Student Download
KEY CONCEPT All vertebrates share common characteristics. • Vertebrates: • Endoskeleton allows vertebrates to grow to large sizes. • internal • made of bone or • cartilage
There are seven classes of vertebrates: • Agnatha jawless fish • Chondrichthyes cartilaginous fish with jaws • Osteichthyes bony fish with jaws • Amphibians 4 limbs • Reptilia have an amnion • Aves birds with feathers • Mammals have hair
Agnatha Chondrichthyes Osteichthyes Amphibia Mammalia Aves bony fish birds lamprey amphibians mammals cartilaginous fish FEATHERS Feathers insulate birds from the cold and allow for flight. FOUR LIMBS Four limbs let animals move from the water to life on land. JAWS Jaws helped vertebrates to become successful predators. HAIR Hair helps mammals to maintain constant body temperatures by providing insulation from the cold. VERTEBRAE Vertebrates have a segmented backbone.
cranium cranium cranium gill arches mouth mouth mouth Jaws evolved from gill supports. • Jaws developed from gill arches located around the pharynx. • Jaws gave vertebrates a huge advantage as predators.
Only two groups of jawed fish still exist: • Cartilaginous fish and bony fish are still in existence • Cartilaginous fish have skeletons made of cartilage. • Examples include shark and rays • Bony fish have skeletons made of bone. • Examples include: • The operculum is a bony structure covering and protecting the gills
water flow Fish are vertebrates with gills and paired fins. • Fish use specialized organs called gills to breathe underwater. • sheets of thick, frilly tissue filled with capillaries • take in dissolved oxygen from water, release carbon dioxide
Amphibians were the first animals with four limbs. Tetrapods are vertebrates that have four limbs. • Amphibians can live both on land and in water. • A number of adaptations allow amphibians to live on land. • breathe through skin or with gills or lungs
Amphibians return to the water to reproduce. • Amphibians use many strategies to keep their eggs wet. • lay eggs directly in water • lay eggs on moist ground • wrap eggs in leaves • brood eggs in pocketson the female’s back
Reptiles were the first amniotes • Reptiles share several characteristics. • Ectotherms (cold blooded) & covered with dry scales • reproduce by laying or retaining amniotic eggs • three-chambered heart • Cloaca-the common cavity into which the intestinal, urinary, and generative canals open in birds, reptiles, amphibians, many fishes, and certain mammals
Reptiles were the first amniotes • An amniote has water which protects the embryo
Birds evolved from theropod dinosaurs. • Birds and many theropods share anatomical features. • hollow bones • Feathers • Wings • The oldest undisputed fossilized bird is Archaeopteryx.
All Mammals share 4 anatomical characteristics. • (1) hair to retain heat • (2) mammary glands to produce milk • (3) a middle ear with three bones to hear higher-pitched sounds • (4) chewing jaw to break up food quicker
Modern mammals are divided into three main groups. (1) Monotremes lay eggs. • duck-billed platypus • Echidna: spiny anteaters, belong to the family Tachyglossidae in the monotreme order of egg-laying mammals (2) Marsupials give birth to live young that grow to maturity inside a pouch. • opossum • kangaroo • wombat • koala (3) Eutherians give birth to live young that have completed fetal development. • most familiar mammals • humans