Kingdom AnimaliaKingdom AnimaliaChapter 20Chapter 20

Kingdom Animalia Kingdom Animalia Overview

◦Heterotrophic, acquire food by ingestion

◦Locomotion by means of muscles◦Multicellular, high degree of cell

specialization◦Adult is diploid◦Reproduction usually sexual, with

embryo undergoing developmental stages

30-2

Kingdom Animalia Kingdom Animalia cont’dcont’d

Invertebrates- lack an endoskeleton of bone or cartilage◦All but one animal phylum are

invertebratesVertebrates- have an

endoskeleton of bone or cartilage

Kingdom Animalia Kingdom Animalia cont’dcont’d

Common Name

Phylum Porifera Sponges

Phylum Cnidaria Cniderians

Phylum Platyhelminthes

Flat Worms

Phylum Nematoda Round Worms

Phylum Mollusca Molluscs

Phylum Annelida Annelids

Phylum Arthropoda Arthropods

Phylum Echinodermata

Echinoderms

Phylum Chordata Chordates

Animal diversityAnimal diversity

Fig. 30.1

Evolutionary Tree Fig. 30.2Evolutionary Tree Fig. 30.2Shows the division of Kingdom

Animalia based on major evolutionary stages.

7 major stages◦Multicellularity◦True tissues◦Bilateral Symmetry◦Tube within a tube◦Coelomates◦Segmentation◦Jointed Appendages

spo

ng

es (

Po

rife

ra)

cnid

aria

ns

(Cn

idar

ia)

flat

wo

rms

(Pla

tyh

elm

inth

es)

rou

nd

wo

rms

(Nem

ato

da)

mo

llu

scs

(Mo

llu

sca)

ann

elid

s (A

nn

elid

a)

arth

rop

od

s (A

rth

rop

od

a)

ech

ino

der

ms

(Ech

ino

der

mat

a)

cho

rdat

es (

Ch

ord

ata)

segmentation

Jointed appendages

segmentation

protostomes deuterostomes

coelomates pseudocoelomates

tube-within-a-tubeacoelomates,no body cavity

radial symmetry,two germ layers

true tissues,germ layers

bilateral symmetry,three germ layers

Multi-cellularity

no true tissues,no germ layers

ancestral protist

1

2

3

4

5

6

7

6

Evolutionary trends among Evolutionary trends among animalsanimalsLevel of organization

◦Cellular- no true tissues; sponges◦Tissue-have ectoderm and endoderm;

cnidarians like hydra◦Organ-have ectoderm, endoderm, and

mesoderm; majority of animalsType of body plan

◦Sac-plan- incomplete digestive system; cnidarians

◦Tube-within-a-tube plan-inner tube is digestive system, outer tube is body wall; two openings

30-8

Evolutionary trends among animals Evolutionary trends among animals cont’d.cont’d.Type of symmetry

◦ Asymmetrical-no particular symmetry◦ Radial symmetry-circular organization, can

be bisected in any plane to produce mirror images

◦ Bilateral symmetry-has definite right and left halves; only a cut down the midline will produce mirror images

Type of body cavity◦ Coelom-cavity that contains organs, and is

lined with mesoderm◦ Acoelomate-lacks a body cavity◦ Pseudocoelomate-body cavity incompletely

lined with mesoderm

30-9

Evolutionary trends among animals Evolutionary trends among animals cont’d.cont’d.Segmentation

◦Repetition of body parts◦Molluscs and echinoderms are

unsegmented coelomates◦Annelids, arthropods, and chordates are

segmented coelomates◦Leads to cephalization and specialization

of body partsJointed appendages

◦Specialized for locomotion◦ In arthropods, may be adapted as mouth

parts

30-10

General characteristics of animal General characteristics of animal phylaphyla

Table 30.1 30-11