Introduction to AnimalsIntroduction 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 O2 and give off CO2

• 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 ammoniaLiquid 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

FISHES AMPHIBIANS

REPTILES BIRDS MAMMALS