3.3The Animals Pages

Importance Pets Food Products (leather, rubber) Pollinators Maintain ecosystem health

Symmetry Radial symmetry (central axis) Bilateral symmetry

Bilateral symmetry Embryonic Development Protostomes- the mouth forms before the anus ( worms, molluscs, arthropods) Deuterostome-the anus forms before the mouth (starfish,chordates)

Vertebrates Has a backbone or notochord (flexible rod) Examples: reptiles, birds, mammals, fish, amphibians

Invertebrates The majority of animals have no backbone

Animals motile sensory ability complex behaviour

Animal cells multicellular heterotrophic eukaryotic cells no cell wall, no chloroplast cellular respiration uses O 2 embryo development includes germ layers that differentiate into different organ systems

Complexity Least-phylum Porifera Most-phylum Chordata.

Sponges phylum Porifera – sessile, no nerves

Cnidaria nematocyts-stinging cell

Arthropoda Insects etc.

Germ layers Ectoderm gives rise to shells, scales, feathers, hair, nails. Mesoderm gives rise to circulatory, reproductive, excretory & muscular systems. Endoderm gives rise to lining of gut Coelom- a body cavity containing the internal organs

The vertebrates ClassFeatures ArthropodJointed appendages EchinodermRadial symmetry, 5 or more arms, use hydraulics to move AgnathansNo paired appendages ChondrichthyesPaired appendages, fins are thick ActinopterygiiFins are membrane-like Amphibia Reptilia Mammalia tetrapods AvesTetrapods with forearms modified as wings

Vertebrates Agnathans (lamprey) Chondrichthyes (sharks)

Vertebrates Actinopterygii (bony fish) Amphibia (frogs, salamanders,newts)

Vertebrates Reptilia Aves

Vertebrates mammals

Protostome Animals PhylumExamplesKey features ArthropodaInsects, spiders, lobsters Segmented bodies, jointed appendages, sensory networks, hard outer shell, insects can fly NematodaPinworms, dog heart worm Unsegmented cylindrical bodies, parasites, complete digestive tracts AnnelidaEarthwormSegmented bodies, complete digestive systems, gas exchanged through skin, gills, bristles on outer surface for movement, many are marine

PhylumExamplesKey features MolluscaSnails, clams octopus and squid 3 main unsegmented body parts, a food, a vieceral mass and a mantle that secretes a shell. File-like radula for scraping and boring, complete digestive systems, circulatory systems and gills RotiferaRotifersSmall aquatic animals, use cilia to direct food into their mouths, no respiratory or circulatory system Platyhel- minthes Tapewor ms, liverflukes Flattened, unsegmented worms, Digestive cavity with single opening, no coeloms, parasitic, no circulatory or respiratory system

Human Protostome Interactions CompetitionInsects, such as grasshoppers, and humans eat crops PathogensTapeworms are parasites found in humans VectorsTicks and fleas spread Lyme disease FoodWe eat clams, scallops, shrimp and lobster Economic Benefits Pollination of our crops by bees, Silk from silk moths, Concrete from coral

Starfish Echinoderms are bilateral symmetrical as larvae but radially symmetrical as adults. They typically have tube feet controlled by a water-filled hydraulic system.

Chordates have  A digestive tract with a mouth and anus  A dorsal hollow nerve cord and a notochord (vertebrae)  Segmented body wall muscles

Chordates… A chordate is a vertebrate if it has a dorsal nerve cord with a spinal column and cranium (skull) with separate segments called vertebrae.

Land Animal Adaptions Body FeatureHow it assisted on land Bony skeletonSupport bodies on land Paired limbsFor mobility Waterproof skin Prevents drying out by sun and air Amniotic eggSpecialized membranes and outer shell protect the egg from water loss

Threats to animals Polar bears are threatened by climate change Frogs and salamanders are threatened by pollution Swift foxes are threatened by habitat loss