Introduction to Introduction to AnimalsAnimals

CharacteristicsCharacteristics Multicellular Multicellular

OrganizationOrganization HeterotrophicHeterotrophic Sexual Sexual

reproduction reproduction and and developmentdevelopment

MovementMovement

Multicellular Multicellular OrganizationOrganization Most animals contain large numbers of Most animals contain large numbers of

cells.cells. Humans contain 50 trillion cells.Humans contain 50 trillion cells.

In most animals, there is a division of In most animals, there is a division of labor.labor. Specialization is the adaptation of a cell for a Specialization is the adaptation of a cell for a

particular function.particular function. Tissues are the organization of cells. Cell are Tissues are the organization of cells. Cell are

able to organize by the joining of cells by cell able to organize by the joining of cells by cell junctions.junctions.

Cell specialization has allowed organisms Cell specialization has allowed organisms to evolve and adapt to many environments.to evolve and adapt to many environments.

Animals are Animals are HeterotrophicHeterotrophic

They must obtain They must obtain complex organic complex organic material from other material from other sources.sources.

Most accomplish Most accomplish this through this through ingestion.ingestion.

Digestion is Digestion is accomplished within accomplished within the animal. This the animal. This process extracts the process extracts the carbohydrates, carbohydrates, protein and lipids protein and lipids from the food eaten.from the food eaten.

Sexual Reproduction and Sexual Reproduction and DevelopmentDevelopment

Sexual reproduction restores the Sexual reproduction restores the diploid number and increases diploid number and increases genetic variation.genetic variation.

During the developmental process, During the developmental process, the zygote undergoes many mitotic the zygote undergoes many mitotic divisions. These identical cells divisions. These identical cells must undergo differentiation.must undergo differentiation.

Differentiation is process of cell Differentiation is process of cell becoming different from each other becoming different from each other and being specialized.and being specialized.

MovementMovement Most animal are able Most animal are able

to move. to move. The ability to move The ability to move

results from the results from the interrelations of two interrelations of two types of tissues found types of tissues found only in animals: only in animals: nervous tissue and nervous tissue and muscular tissue.muscular tissue.

There are a few There are a few animals that are animals that are sessile.sessile.

Origin and ClassificationOrigin and Classification The first animals The first animals

probably arose from the probably arose from the sea. sea.

Taxonomists have Taxonomists have grouped animals into grouped animals into several phyla based on several phyla based on evolutionary evolutionary relationships.relationships.

Many taxonomist Many taxonomist recognize 30 or more recognize 30 or more animal phyla. We will animal phyla. We will investigate 11 phyla. investigate 11 phyla. Ten of the phyla include Ten of the phyla include invertebrates and only invertebrates and only Chordata includes the Chordata includes the vertebrates.vertebrates.

Animal Body Animal Body StructureStructure

SymmetrySymmetryGerm layersGerm layersBody CavitiesBody Cavities

SymmetrySymmetry Asymmetry refers to the consistent Asymmetry refers to the consistent

overall pattern of structure of an overall pattern of structure of an animal.animal.

Animals have three patterns of Animals have three patterns of symmetry.symmetry. Asymmetry – no symmetryAsymmetry – no symmetry Radial Symmetry – similar parts Radial Symmetry – similar parts

branch in all directions from a branch in all directions from a central pointcentral point

Bilateral Symmetry- similar halves Bilateral Symmetry- similar halves on either side of a central plane.on either side of a central plane.

Patterns of SymmetryPatterns of Symmetry

Identify the Type of Identify the Type of SymmetrySymmetry

Most animals have a dorsal, Most animals have a dorsal, ventral, anterior and ventral, anterior and posterior side or orientation.posterior side or orientation. Dorsal – topDorsal – top Ventral – bottomVentral – bottom Anterior – headAnterior – head Posterior - tailPosterior - tail

Most animals exhibit Most animals exhibit cephalization, the cephalization, the concentration of sensory and concentration of sensory and brain structures in the brain structures in the anterior. Animals with anterior. Animals with cephalization have a head!cephalization have a head!

Germ LayersGerm Layers

Germ layers are Germ layers are fundamental fundamental tissue types tissue types found in all found in all animals except animals except sponges (no true sponges (no true tissues).tissues). EctodermEctoderm MesodermMesoderm EndodermEndoderm

Body CavitiesBody Cavities

Most animals have Most animals have a fluid filled space a fluid filled space that forms that forms between the between the digestive tract and digestive tract and the outer wall of the outer wall of the body during the body during development. This development. This space is known as space is known as a a COELOMCOELOM..

Acoelomate (without a coelom) Acoelomate (without a coelom) 2 germ layers2 germ layers

ectoderm and endoderm ectoderm and endoderm not separated by a cavity not separated by a cavity least complex body plan least complex body plan sponges and cnidarians sponges and cnidarians

3 layer acoelomate 3 layer acoelomate 3 germ layers3 germ layers

endoderm, mesoderm and ectoderm endoderm, mesoderm and ectoderm not separated by a cavity not separated by a cavity flatworms flatworms

Pseudocoelomate Pseudocoelomate pseudocoelom pseudocoelom cavity formed between mesoderm and endoderm cavity formed between mesoderm and endoderm roundworms and rotifers roundworms and rotifers

Coelomate Coelomate cavity developed within the mesoderm cavity developed within the mesoderm most complex body plan most complex body plan mollusks, annelids, arthropods, echinoderms, and mollusks, annelids, arthropods, echinoderms, and

chordateschordates

Animal DiversityAnimal Diversity InvertebratesInvertebrates

10 phyla10 phyla 95% of animals95% of animals

ChordatesChordates NotochordNotochord Dorsal nerve cordDorsal nerve cord Pharyngeal pouchesPharyngeal pouches Postanal tailPostanal tail

VertebratesVertebrates Include fishes, birds Include fishes, birds

and mammalsand mammals

Kingdom Animalia

Invertebrates Chordates

Vertebrates

What is the What is the difference in a difference in a

vertebrate and an vertebrate and an invertebrate?invertebrate?

A vertebrate is an animal A vertebrate is an animal with a backbone and with a backbone and

invertebrates do not have invertebrates do not have a backbonea backbone..

Comparison of Invertebrates and Comparison of Invertebrates and VertebratesVertebratesInvertebrateInvertebrate VertebrateVertebrate

symmetrysymmetry

germ layersgerm layers

Body cavitiesBody cavities

SegmentationSegmentation

supportsupport

Respiratory/Respiratory/

circulatorycirculatory

Digestive/Digestive/excretoryexcretory

NervousNervous

reproductionreproduction