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:1. Agnatha jawless fish2. Chondrichthyes cartilaginous fish

with jaws3. Osteichthyes bony fish with jaws4. Amphibians 4 limbs5. Reptilia have an amnion6. Aves birds with feathers7. Mammals have hair

Agnatha Chondrichthyes Osteichthyes Amphibia Aves Mammalia

JAWSJaws helped vertebrates to become successful predators.

VERTEBRAEVertebrates have a segmented backbone.

FOUR LIMBSFour limbs let animals move from the water to life on land.

FEATHERSFeathers insulate birds from the cold and allow for flight.

HAIRHair helps mammals to maintain constant body temperatures by providing insulation from the cold.

lam

prey

cart

ilagi

nous

fish

bony

fish

am

phi b

ian s

bird

s

mam

mal

s

Jaws evolved from gill supports.

• Jaws developed from gill arches located around the pharynx.

cranium

mouth gill arches

cranium

mouth

cranium

mouth

• 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

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

waterflow

• A number of adaptations allow amphibians to live on land.– breathe through skin or

with gills or lungs

• Amphibians can live both on land and in water.

Amphibians were the first animals with four limbs. Tetrapods are vertebrates that have four limbs.

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 pockets

on 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

• An amniote has water which protects the embryo

Reptiles were the first amniotes

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