Introduction to Animals INTRODUCTION TO ANIMALS Most diverse

Introduction to Animals

INTRODUCTION TO ANIMALS • Most diverse kingdom in appearance • More than 1 million species! • Each phylum has its own typical body plan (arrangement)

WHAT IS AN ANIMAL? • • • Animals: are heterotrophic are eukaryotic are multicellular lack cell walls

WHAT IS AN ANIMAL? • 95% = invertebrates (do not have backbone) • 5% = vertebrates (have a backbone)

WHAT IS AN ANIMAL? • Anatomy = the structure of the organism/organs what it is • Physiology = study of the functions of organs how it works

WHAT IS AN ANIMAL? • Homeostasis (balance) is maintained by internal feedback mechanisms • Ex: dog panting releases heat, you sweat to release heat

FUNCTIONS OF ANIMALS • Feeding animals must obtain energy by eating • Examples of types of feeding: – – – Herbivore = eats plants Carnivore = eats animals Omnivore = eats plants and animals Scavenger = eats dead organisms Detritivore = feed on decaying organic material Filter Feeders = aquatic animals that strain food from water – Parasite = lives in or on another organism (symbiotic relationship)

FUNCTIONS OF ANIMALS • Respiration animals require oxygen • Take in O 2 and give off CO 2 • Lungs, gills, through skin, simple diffusion

FUNCTIONS OF ANIMALS • Circulation animals must move necessary materials within their bodies • Very small animals rely on diffusion • Larger animals have circulatory system

FUNCTIONS OF ANIMALS • Excretion animals must expel waste • Primary waste product is ammonia Liquid waste

FUNCTIONS OF ANIMALS • Response animals respond to a stimulus • Receptor cells = sound, light, external stimuli • Nerve cells = nervous system

FUNCTIONS OF ANIMALS • Movement • Most animals are motile (can move) • Muscles usually work with a skeleton

FUNCTIONS OF ANIMALS • Reproduction animals must reproduce • Most reproduce sexually = genetic diversity • Many invertebrates can also reproduce asexually = to increase their numbers rapidly

LEVELS OF ORGANIZATION • Cell Specialization and Levels of Organization: cells tissues organ systems

EARLY DEVELOPMENT • Zygote = fertilized egg • Blastula = a hollow ball of cells • Blastopore = the blastula folds in creating this opening • Protostome = mouth is formed from blastopore • Deuterostome = anus is formed from blastopore • Anus = opening for solid waste removal from digestive tract

EARLY DEVELOPMENT • The cells of most animal embryos differentiate into three layers called germ layers: • Endoderm = (innermost) develops into the lining of the digestive tract and respiratory tract • Mesoderm = (middle) muscle, circulatory, reproductive, and excretory systems • Ectoderm = (outermost) sense organs, nerves, outer layer of skin

BODY SYMMETRY • Body Symmetry - the body plan of an animal, how its parts are arranged • Asymmetry - no pattern (corals, sponges)

BODY SYMMETRY • Body Symmetry - the body plan of an animal, how its parts are arranged • Radial Symmetry - shaped like a wheel (starfish, hydra, jellyfish)

BODY SYMMETRY • Body Symmetry - the body plan of an animal, how its parts are arranged • Bilateral Symmetry - has a right and left side (humans, insects, cats, etc)

CEPHALIZATION • Cephalization - an anterior concentration of sense organs (to have a head) • The more complex the animals becomes the more pronounced their cephalization

BODY PLAN • • anterior - toward the head posterior - toward the tail dorsal - back side ventral - belly side

SEGMENTATION • Segmentation - "advanced" animals have body segments and specialization of tissue (even humans are segmented, look at the ribs and spine)

BODY CAVITY • Body Cavity Formation: A fluid-filled space where internal organs can be suspended

TYPES OF ANIMALS • • Phylum Porifera Typically asymmetrical Lack tissues and organs Adults are sessile Mostly marine Sexual and asexual reproduction Example: sponges About 10, 000 species

TYPES OF ANIMALS • • • Phylum Cnidaria Radially symmetrical Have distinct tissues Marine and freshwater Examples: jellyfish, hydra, coral About 10, 000 species

TYPES OF ANIMALS • Phylum Ctenophora • Radially symmetrical • Transparent, gelatinous marine animals resembling jellyfishes • Propelled by cilia • Examples: comb jellies • About 100 species

TYPES OF ANIMALS • • Phylum Platyhelminthes Bilaterally symmetrical Acoelomates Body flat and ribbon-like Lack true segments Organs present Examples: Planaria, Tapeworm, Schistosoma • More than 18, 000 species

TYPES OF ANIMALS • • • Phylum Nematoda Roundworms Body slender and elongated Pseudocoelomates Oneway gut Examples: Ascaris, pinworms, hookworms, Trichinella, and Wuchereria • More than 80, 000 species

TYPES OF ANIMALS • Phylum Rotifera • Small, transparent, wormlike or spherical animals • Bilaterally symmetrical • Pseudocoelomates • Almost all live in fresh water • Example: rotifers • About 1, 750 species

TYPES OF ANIMALS • • • Phylum Annelida Bilaterally symmetrical Serially segmented worms Protostomes Examples: earthworms, leeches About 15, 000 species

TYPES OF ANIMALS • • Phylum Mollusca Soft-bodied animals Coelomates Protostomes most have a radula Terrestrial, freshwater, and marine Examples: clams, octopuses, snails More than 110, 000 species

TYPES OF ANIMALS • • • Phylum Arthropoda Bilaterally symmetrical Coelomates Protostomes Segmented bodies Paired , jointed appendages Chitinous exoskeleton Aerial, terrestrial, and aquatic forms Examples: insects, spiders, crustaceans About 1 million species

TYPES OF ANIMALS • Phylum Echinodermata • Adults are radially symmetrical – five-part body plan • Coleomates • Deuterostomes • Most forms have a water vascular system with tube feet for locomotion • Marine • Examples: sea star, sand dollar, sea urchin • About 7, 000 species

TYPES OF ANIMALS • • • Phylum Chordata Bilaterally symmetrical Deuterostomes Coelomates Have – – A notochord (early backbone and spinal cord) A dorsal nerve cord Pharyngeal slits A tail at some stage of life • Aquatic and terrestrial • Examples: fishes, amphibians, reptiles, birds, mammals • More than 47, 000 species

Phylum Chordata FISHES REPTILES AMPHIBIANS BIRDS MAMMALS