Chapter 32Introduction to Animals

Characteristics

• Multicellular• Specialization (cells, tissue, organs, and organ systems = particular

function) • Heterotrophs – ingestion• Sexual and Asexual reproduction – zygote and differentiation• Movement – most have ability to move

1. Invertebrates - no backbone• Over 95% of all animals• Insects, Worms, Jellies, Sea Stars, Etc.2. Vertebrates - backbone• Other 5%• Fish, Amphibian, Reptile, Bird, Mammal

2 Categories

1. Feeding - most ingest 2. Respiration - take in O2 & give off CO23. Circulation - move oxygen, nutrients, waste, water

thru body4. Excretion - wastes (ammonia)5. Response - respond to environ. thru nerve cells6. Movement - thru muscles7. Reproduction - most sexual, some asexual

Animal Functions

1. Asymmetry - no symmetry• Sponges only2. Radial - body parts repeat around center of body

(many ways to divide into equal halves)• Sea star, sea anemone, jellyfish3. Bilateral - one way to divide body in half (left, right,

front, back)• All other animals

Body Symmetry

Body Symmetry

Symmetry

Origin and Classification

• First animals probably arose in the sea• Invertebrates – first multicellular animals; evolved from

protists• Cell speciation

• Scientists use a branching diagram to show how animals are related through evolution (pg. 653): Phylogenic Diagram

Phylogenic Diagram

Evolutionary Relationships

Smaller the category the more related the organisms are:

DNA & RNA sequences

Shared a common ancestorUse cladograms to show evolutionary relationships

Cladogram

CladogramCloser together on

cladogram = the more closely related

Ex: bird & croc closeEx: bird & shark not close

Binomial Nomenclature

• Carolus Linnaeus - Swedish botanist 1700’s• 2 word naming system• Latin, Italicized, first word capitalized• Ex: Ursus maritimus - polar bear• Ursus = genus (closely related species -bears)• 2nd name = species - describes a trait

Binomial NomenclatureUrsus maritimus

Ursus arctos

Classification System

• Largest to smallest:• Kingdom (Ken)• Phylum (Poured)• Class (Coffee)• Order (On)• Family (Fred’s)• Genus (Green)• Species (Shirt)

KingdomLargestLinnaeus 2 kingdoms:

plant & animalCurrent 6 Kingdoms:

Archaebacteria, Eubacteria, Plant, Animal, Fungi, Protist

Invertebrate Characteristics• Radial or bilateral symmetry• Segmentation• Simple skeletons (sponge), exoskeletons, fluid-filled pressure• Gas exchange across body covering or through gills• Open or closed circulatory system• Digestion by individual cells or through gut• Simple to diverse nervous systems• Sexual and asexual reproduction• Indirect (laval stage) or Direct (looks like adult) development

Vertebrate Characterisitis• Backbone – vertebrae (segmented)• Endoskeleton • Bilateral symmetry• Integument (outer covering of skin)• Gills = aquatic vertebrates• Lungs = terrestrial verts• Digestion = gut and associated organs• Highly organized brains and nervous system• External (fish/amphibians) and Internal Fertilization• External development and Internal development (placental)

Fertilization and Development

• Book work