Introduction to AnimalsIntroduction to AnimalsEssential Questions:Essential Questions:

What makes an animal an animal?What makes an animal an animal?

How are animals classified?How are animals classified?

Kingdom AnimaliaKingdom Animalia EukaryoticEukaryotic HeterotrophicHeterotrophic MulticellularMulticellular

Tissues and organsTissues and organs formed by specialized cells formed by specialized cells

No cell wallsNo cell walls

Likely evolved from Likely evolved from animal-like animal-like protistsprotists

Essential FunctionsEssential Functions

All animals carry out the following:All animals carry out the following:1.1. Obtain food from the environmentObtain food from the environment

2.2. Exchange OExchange O22 & CO & CO2 2 through skin, gills, lungs, etcthrough skin, gills, lungs, etc

3.3. Move materials around bodyMove materials around body

4.4. Get rid of wastesGet rid of wastes

5.5. Process information with nervesProcess information with nerves

6.6. All animals are motile at some pointAll animals are motile at some point

7.7. Most reproduce sexually, some asexuallyMost reproduce sexually, some asexually

Reproduction & DevelopmentReproduction & Development Animals mainly reproduce Animals mainly reproduce sexuallysexually

FertilizationFertilization – sperm meets egg, either within – sperm meets egg, either within or outside the bodyor outside the bodyExternalExternal fertilization (in water) fertilization (in water)InternalInternal fertilization (on land) fertilization (on land)

What are the positives What are the positives

and negatives of each and negatives of each

type of fertilization?type of fertilization?

Reproduction & DevelopmentReproduction & Development Steps of Development:Steps of Development:

Fertilization results in a Fertilization results in a unicellular unicellular zygotezygote

The unicellular The unicellular zygotezygote divides divides by by mitosismitosis = = cleavagecleavage

A hollow ball of cells A hollow ball of cells ((blastula)blastula) formsforms

GastrulationGastrulation (folding inward) (folding inward) forms 2 cells layers: forms 2 cells layers: ectodermectoderm and and endodermendoderm

MesodermMesoderm forms forms

Coelomate vs AcoelomatesCoelomate vs Acoelomates CoelomCoelom – fluid filled cavity that supports internal – fluid filled cavity that supports internal

organs.organs. AcoelomatesAcoelomates – no internal cavity. – no internal cavity. ExampleExample: Flatworms: Flatworms PseudocoelomatesPseudocoelomates – body cavity develops between – body cavity develops between

endoderm and mesoderm. endoderm and mesoderm. ExampleExample: Roundworms: Roundworms CoelomatesCoelomates – internal organs suspended in a body – internal organs suspended in a body

cavity surrounded by mesoderm. cavity surrounded by mesoderm. ExampleExample: Earthworms: Earthworms

Why the Coelom?The coelom is significant because as animals evolved, so did the presence of a complex body cavity to support more complex organs!

SymmetrySymmetry Animals can be described in terms of their symmetry: Animals can be described in terms of their symmetry: AsymmetryAsymmetry – irregular in shape – irregular in shape ExampleExample: Sponge: Sponge Radial SymmetryRadial Symmetry – can be divided through along any plane – can be divided through along any plane

into halves from the mouth. into halves from the mouth. ExampleExample: Anemone: Anemone Bilateral SymmetryBilateral Symmetry – can be divided lengthwise into 2 mirror – can be divided lengthwise into 2 mirror

images.images. Example Example: Humans: Humans CephalizationCephalization: concentration of sense organs at the front : concentration of sense organs at the front

(top) of the body(top) of the body

Body PositioningBody Positioning

Bisymmetrical animalsBisymmetrical animals have have 4 parts4 parts::

AnteriorAnterior: the head end, : the head end, where sensory organs are where sensory organs are locatedlocated

PosteriorPosterior: the tail end : the tail end (anus)(anus)

DorsalDorsal: Back surface where : Back surface where the spine is locatedthe spine is located

VentralVentral: The belly side: The belly side

Framework for support: SkeletonsFramework for support: Skeletons ExoskeletonsExoskeletons – hard, waxy – hard, waxy

covering on the exterior of the covering on the exterior of the body. body. Prevent water loss, protect soft Prevent water loss, protect soft

tissuestissues

EndoskeletonsEndoskeletons – internal skeleton – internal skeleton for support made of for support made of Calcium Calcium CarbonateCarbonate, , cartilagecartilage or or bonebone Protects internal organs and an Protects internal organs and an

internal brace for muscles to pull internal brace for muscles to pull againstagainst

To survive on land, why is it important to have a strong skeleton?

Framework for support: SkeletonsFramework for support: Skeletons InvertebratesInvertebrates – an – an

animal without a animal without a backbone; usually has backbone; usually has exoskeletonexoskeleton Echinoderms have Echinoderms have

endoskeletonsendoskeletons

VertebratesVertebrates – an animal – an animal with a backbone; with a backbone; bilaterally symmetry; bilaterally symmetry; exoskeletonexoskeleton

InvertebratesInvertebrates Make up 95% of all animalsMake up 95% of all animals No backboneNo backbone, or vertebral column. , or vertebral column.

Most have Most have exoskeletonsexoskeletons.. Open circulatory systems (with a one Open circulatory systems (with a one

chambered “heart”)chambered “heart”) Cannot process Cannot process OxygenOxygen very well, restricts very well, restricts

their size and survival on land.their size and survival on land.

Invertebrate PhylaInvertebrate Phyla

Phylum Phylum PoriferaPorifera - Sponges - Sponges Phylum Phylum CnidariaCnidaria – Corals, Hydra & – Corals, Hydra &

JellyfishJellyfish Phylum Phylum PlatyhelminthesPlatyhelminthes - Flatworms - Flatworms Phylum Phylum NematodaNematoda – Roundworms – Roundworms Phylum Phylum MolluscaMollusca – Snails, squid & – Snails, squid &

ClamsClams Phylum Phylum AnnelidaAnnelida - Segmented Worms - Segmented Worms Phylum Phylum ArthropodaArthropoda – Insects, spiders, – Insects, spiders,

lobsterslobsters Phylum Phylum EnchinodermataEnchinodermata – Starfish – Starfish Invertebrate members of Phylum Invertebrate members of Phylum

ChordataChordata– Sea squirts, Lancelets– Sea squirts, Lancelets

Phylum AnnelidaPhylum Annelida

The segmented The segmented worms. worms. Example: Example: earthworms, leechesearthworms, leeches

Segmentation Segmentation allows movement allows movement of individual partsof individual parts

Possess a true Possess a true coelomcoelom

Specialized organs Specialized organs and systemsand systems

Phylum Chordata Phylum Chordata Subphylum VertebrataSubphylum Vertebrata

Class Agnatha (jawless fishes) Class Chondrichthyes

(cartilaginous fishes) Class Osteichthyes (bony fishes) Class Amphibia (amphibians) Class Reptilia (reptiles) Class Aves (birds) Class Mammalia (mammals)

VertebratesVertebrates 5% of all animals5% of all animals Have aHave a vertebral column.vertebral column.

The The backbonebackbone gives gives supportsupport to the to the body and body and protectionprotection to the spinal to the spinal cordcord

Have Have endoskeletonsendoskeletons.. Closed circulatory systemClosed circulatory system with with

a a multichamberedmultichambered heart heart

ClassificationClassification: Kingdom – Animalia, : Kingdom – Animalia, Phylum – Chordata, Subphylum - Phylum – Chordata, Subphylum - VertebrataVertebrata

Types of MammalsTypes of Mammals Subclasses – based on type Subclasses – based on type

of reproductionof reproduction PlacentalPlacental (95%) – young fully (95%) – young fully

develops in uterus before birthdevelops in uterus before birth MarsupialsMarsupials – short period of – short period of

development inside the mother development inside the mother followed by a second period of followed by a second period of development inside pouchdevelopment inside pouch

MonotremesMonotremes - lay eggs. # - lay eggs. # species: platypus and 2 species: platypus and 2 echidnasechidnas

Vertebrates: Am I hot or not?Vertebrates: Am I hot or not? The major difference between The major difference between

vertebrates is whether or not they can vertebrates is whether or not they can regulate their own body temperature.regulate their own body temperature.

EctothermsEctotherms – regulated by – regulated by environment environment

ExampleExample: fish, frogs, snakes: fish, frogs, snakes

EndothermsEndotherms – regulated by their – regulated by their own body own body

ExampleExample: mammals: mammals

Animals that are ectothermic (like snakes) don’t Animals that are ectothermic (like snakes) don’t require food as much as endotherms.require food as much as endotherms.

• • What does this indicate about the relationship What does this indicate about the relationship between food requirements and the generation of between food requirements and the generation of

body heat?body heat? • • How does this fact restrict where certain types How does this fact restrict where certain types of animals can live?of animals can live? • • If the environment were to suddenly get cold If the environment were to suddenly get cold (like an ice age), which of the (like an ice age), which of the animals could survive?animals could survive?