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  organs  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 FISHESAMPHIBIANS REPTILES BIRDSMAMMALS