Download Introduction to Animals Notes

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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
•95% = invertebrates (do not have backbone)
•5% = vertebrates (have a backbone)
•Anatomy = the structure of the organism/organs
what it is
•Physiology = study of the functions of organs
how it works
•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)
•Respiration animals require oxygen
•Take in O2 and give off CO2
•Lungs, gills, through skin, simple diffusion
•Circulation  animals must move necessary materials within their bodies
•Very small animals rely on diffusion
•Larger animals have circulatory system
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•Excretion  animals must expel waste
•Primary waste product is ammonia
Liquid waste
•Response  animals respond to a stimulus
•Receptor cells = sound, light, external stimuli
•Nerve cells = nervous system
Movement 
•Most animals are motile (can move)
•Muscles usually work with a skeleton
•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
•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)
•Radial Symmetry - shaped like a wheel (starfish, hydra, jellyfish)
•Bilateral Symmetry - has a right and left side (humans, insects, cats, etc)
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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
•Phylum Cnidaria
•Radially symmetrical
•Have distinct tissues
•Marine and freshwater
•Examples: jellyfish, hydra, coral
•About 10,000 species
•Phylum Ctenophora
•Radially symmetrical
•Transparent, gelatinous marine animals resembling jellyfishes
•Propelled by cilia
•Examples: comb jellies
•About 100 species
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•Phylum Platyhelminthes
•Bilaterally symmetrical
•Acoelomates
•Body flat and ribbon-like
•Lack true segments
•Organs present
•Examples: Planaria, Tapeworm, Schistosoma
•More than 18,000 species
•Phylum Nematoda
•Roundworms
•Body slender and elongated
•Pseudocoelomates
•Oneway gut
•Examples: Ascaris, pinworms, hookworms, Trichinella, and Wuchereria
•More than 80,000 species
•Phylum Rotifera
•Small, transparent, wormlike or spherical animals
•Bilaterally symmetrical
•Pseudocoelomates
•Almost all live in fresh water
•Example: rotifers
•About 1,750 species
•Phylum Annelida
•Bilaterally symmetrical
•Serially segmented worms
•Protostomes
•Examples: earthworms, leeches
•About 15,000 species
•Phylum Mollusca
•Soft-bodied animals
•Coelomates
•Protostomes
•most have a radula
•Terrestrial, freshwater, and marine
•Examples: clams, octopuses, snails
•More than 110,000 species
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•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
•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
•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