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

Cladogram

Closer 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 Nomenclature

Ursus maritimus

Ursus arctos

Classification System

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

Kingdom

LargestLinnaeus 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