The Animal Kingdom Bio 100 Tri-County Technical College Pendleton, S. C

General Features of Animals Movement of the entire animal or movement of a part of the animal. Heterotrophic mode of nutrition Soft Bodies Respond quickly and appropriately to changes in their environment Sexual reproduction

Some few animals reproduce asexually and sexually. Eucaryotic cells No cell walls Multicellular forms organized into tissues, organs, and organ systems

Asexual vs. Sexual Reproduction Asexual reproduction –some part of the animal body detaches and grows into an exact duplicate of the parent –no variation Sexual reproduction –union of egg and sperm results in an organism that is similar to parents but not exactly like them

Temperature Regulation Ectotherms –body temperature varies –“cold-blooded” –reptiles Endotherms –maintain a constant body temperature –“warm-blooded” –mammals

Body Symmetry Asymmetry –no regular body form –sponges Radial symmetry –“pie” symmetry Bilateral symmetry –one plane divides the body into two halves that are mirror images of each other

Tubular Bodies Most animals with bilateral symmetry –body structure composed of 3 layers –tube within a tube –outer tube muscles and nerves –inner tube digestive system with a mouth at one end and an anus at the other

Coelomate vs. Acoelomate coelom –body cavity between the two tubes coelomate animals have a coelom –advanced animals: earthworms, insects, reptiles, birds, and mammals acoelomate, pseudocoelomate –do not have coelom –simple animals: jellyfish and flatworms

Vertebrate vs. Invertebrate Invertebrate –don’t have a backbone –invertebrate phyla: Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata Vertebrate –have a back bone (vertebral column –vertebrate phylum: Chordata (Vertebrata)

THE ANIMAL KINGDOM

Phylum Porifera the sponges water circulates through the body marine and freshwater forms adults are anchored to something –sessile pattern of existence most exhibit radial symmetrical no true tissues

Phylum Cnidaria hydras, jellyfish, sea anemones, and coral reef radial symmetry tentacles and stinging cells marine mostly incomplete digestive tract

Phylum Platyhelminthes flatworms--prefix “platy” means flat bilateral symmetry no body cavity incomplete digestive system planaria, tapeworms, and flukes some cause human disease: tapeworms and flukes

Phylum Nematoda roundworms cuticle covered body pseudocoelom complete digestive tract-mouth and anus some parasites and some free-living pinworm disease in humans plant root nematodes

Phylum Mollusca muscular foot for locomotion many have a calcium carbonate shell complete digestive tract have a true body cavity body is not segmented clams, squids, snails many use gills for respiration

Phylum Annelida segmented worms body segmentation complete digestive tract true body cavity bilateral symmetry earthworms and leeches

Phylum Arthropoda bilateral symmetry tough exoskeleton segmented: head, thorax, and abdomen joint-legged insects, spiders, crustaceans, centipedes, and millipedes tremendous numbers

Phylum Echinodermata spiny-skinned animals no body segmentation larval stages bilaterally symmetrical adults radially symmetrical water vascular system--tube feet endoskeleton under spiny skin starfish and sea urchins

Phylum Chordata bilateral symmetry segment body with endoskeleton well-developed body cavity single, dorsal nerve cord enlarged anterior end of nerve cord (brain) tail at some stage of development complete digestive system

Subphylum Vertebrata vertebral column to protect spinal cord movement by muscles attached to endoskeleton complete digestive system with large digestive glands ventral heart with 2-4 chambers blood with RBC’s and WBC’s

well-developed body cavity paired kidneys with drainage to exterior general body plan –head –trunk –2 pairs of appendages –postanal tail

Classes of Vertebrates Class Agnatha -- jawless fishes Class Chondrichthyes -- cartilaginous fishes Class Osteichthyes -- bony fishes Class Amphibia -- amphibians Class Reptilia -- reptiles Class Aves -- birds Class Mammalia: mammals

Class Agnatha “Jawless” fish Hagfish and lampreys Some are parasites that suck the blood out of host

Class Chondrichthyes cartilaginous skeleton sharks, rays, and skates

Class Osteichthyes skeleton made of bone similar to ours bony fishes

Class Amphibia frogs, newts, and salamanders made a partial break from water

Class Reptilia turtles, snakes, lizards made a complete break from water have lungs and water proofed skin

Class Aves birds only vertebrates with feathers

Class Mammalia have hair over most of the body have mammary glands that produce milk specialized teeth feed newborns with milk hair modified to spines in some mammals 4 chambered heart

Mammals, ctd. Monotremes are egg-laying mammals –Duck-bill platypus one of three existing species –Females do not have nipples Marsupials are the pouched mammals –Kangaroos, koalas, opossums –Deliver offspring that complete development in pouch Eutherians (placental mammals…but) –Deliver well-developed offspring