Miss Hillemann College Prep Biology Neshaminy High School KingDom Animalia Miss Hillemann College Prep Biology Neshaminy High School

Comparisons of kingdoms in Domain Eukarya

What is an Animal? Four key characteristics: Eukaryotic. Lack cell walls. Multicellular Heterotrophs that ingest food.

Invertebrates & vertebrates Invertebrates: animals without backbones 95% of animals Most live in aquatic or moist terrestrial habitats Examples: sea stars, jellyfish, snails, clams, insects, and worms Vertebrates: animals with backbones Mainly terrestrial, but also live in marine and freshwater habitats Examples: fishes, frogs, snakes, dogs, humans

Animal life Cycle Adult male and female animals produce haploid gametes by meiosis Fertilization: an egg and a sperm fuse to form a diploid zygote zygote undergoes mitosis First several cell divisions leads to a blastula in all animals Typically consists of a single layer of cells surrounding a hollow cavity

Animal life Cycle Later, in many animals, one side of blastula folds inward to form a gastrula. Has an outer and an inner cell layer Many animals then develop directly into adults. Others (i.e. sea star) go through one or more larval stages Larva: immature form of an animal that looks different from the adult forms and usually eats different food. Larva undergoes metamorphosis to become an adult.

Life Cycle of a Sea Star

Chapter 23 Invertebrate Animals

IMPORTANT TERMINOLOGY Coelom: fluid-filled body cavity that is lined by tissue Coleomates: have a coelom Acoelomates: lack a coelom Closed Circulatory System: blood remains contained within vessels Open Circulatory System: blood vessels open into chambers where the organs are bathed directly in blood

PHYLUM PORIFERA (SPONGES) Simplest animals. Lack true tissues and organs Relatively unspecialized cells No body symmetry Adults are sessile—anchored in place Chemical defenses

PHYLUM CNIDARIA (CNIDARIANS) Radial symmetry Basic tissues. Slow-moving or sessile Tentacles with stinging cells (cnidocytes) The mouth leads into a digestive sac called the gastrovascular cavity. Undigested food and wastes exit back through the mouth

DIVERSITY OF CNIDARIANS 2 body forms: Polyp: cylindrical body with tentacles radiating from one end. Sessile Examples: hydras, sea anemones Medusa: umbrella-shaped form with fringes of tentacles around the lower edge Examples: jellyfish Some cnidarian life cycles include both a medusa and a polyp stage.

PHYLUM PLATYHELMINTHES (FLATWORMS) Bilateral symmetry Three tissue layers: Ectoderm body covering Mesoderm tissue layer Endoderm  digestive sac. Gastrovascular cavity Food enters and wastes leaves from one opening on bottom surface Ex: flukes, tapeworms, planarians Bilateral Symmetry

PHYLUM NEMATODA (ROUNDWORMS) Round body No segments Complete digestive tract with 2 openings: a mouth and an anus Very diverse--15,000 species Ex: rotifers, hookworm, pinworm, threadworm

ANNELIDS Round body Segmented Closed circulatory system acoelomates

PHYLUM MOLLUSCA (MOLLUSKS) Soft body protected by a hard shell Mantle: Muscular foot coelomates Open circulatory system Ex: land snails, slugs, clams, oysters, mussels, scallops, squids, octopuses

PHYLUM ECHINODERMATA (ECHINODERMS) Lack body segments Rough and spiny surface Water vascular system: network of water-filled canals Tube feet: function in locomotion, feeding, and respiration Larvae bilateral symmetry, Adults radial symmetry Examples: sea urchins, sea stars, brittle stars, sea lilies, sea cucumbers, sea daisies

PHYLUM ARTHROPODA (ARTHROPODS) Segmented bodies Jointed appendages Exoskeleton (hard external skeleton) of protein and chitin As it grows, it sheds its exoskeleton and secretes a new one (molting) Open circulatory system Ex: insects, crustaceans, spiders

Chapter 24 VERTEBRATE ANIMALS

FISHES 2 main groups: aquatic Sexual reproduction 2-chambered heart Cartilaginous: flexible skeleton made of cartilage Bony: skeletons contain bone hardened by calcium compounds aquatic Sexual reproduction 2-chambered heart gills

AMPHIBIANS Larval stage (tadpoles) lives in water, while adult stage lives on land Gills as larva, lungs and moist skin in adults Sexual reproduction 3-chambered heart Ex: frogs, salamanders, caecilians (legless and blind)

REPTILES Amniotes: amniotic egg (waterproof egg with a shell), internal fertilization, and water-tight skin Most lay eggs, though some give birth to live young Ectotherms: main source of body heat is external environment Scaly skin Ex: turtles, lizards, snakes, crocodiles, alligators

BIRDS Specialized wing shape and hollow bones for flight Feathers Endotherms: body heat generated from cell metabolism Gizzards: muscular organ that grinds seeds and other food 4-chambered heart Sexual reproduction

MAMMALS Endotherms Mammary glands: produce milk in female mammals Hair or fur Lungs Sexual reproduction 4-chambered heart Ex: deer, wolves, elephants, giraffes, tigers, dogs, cats, humans

MONOTREMES Mammals that lay eggs Mixture of ancestral reptilian traits and mammalian characteristics Ex: platypuses, echidnas Platypus