Kingdom Animaliapage 657

What is an animal?

What are characteristics of animals?

• http://www.youtube.com/watch?v=Gw0FU733zzg

Characteristics of animals

1. Multicellular– Different cells specialize to perform certain

functions– As specialization increases, so does complexity

and this enables animals to adjust better to their environments.

Characteristics continued

2. Eukaryotic3. Heterotrophic - ingest and then digest inside

body4. Most are motile

Characteristics continued

5. Phyla in the animal kingdom are classified according to evolutionary development.

a. 2 subkingdoms: parazoa (less evolved) and metazoa

b. Also grouped by whether they are:

vertebrates or

invertebrates (95%)

Animals carry out the following essential functions and each has adaptations which allow it to do so:

• Feeding– Ingest–herbivores, carnivores, omnivores

• Respiration–Oxygen in; carbon dioxide out

• Circulation–Diffusion in small, aquatic– Larger animals have a circulatory system.

• Excretion–Main waste product of cells is ammonia

(contains nitrogen)–Most animals have an excretory system that

eliminates ammonia or changes it into a less toxic substance and then gets rid of it

• Response–Respond to events in their environments

using specialized nerve cells.

• Movement–Majority of animals are motile (capture

food)–Some may be sessile as adults but move

in early development.–When sessile, they attach themselves to

a spot and capture food as it passes by.

• Reproduction– Sexual (haploid gametes) which maintains

genetic diversity– In some cases, may be asexual, which

allows for rapid reproduction

Also see page 660

Degree of specialization

a. Cells which are grouped together to formb. Tissues such as blood, bone, muscle,

nervec. Organs: liver, stomachd. Organ systems: circulatory, digestive,

reproductive

Early development – page 661

• Zygote = fertilized egg• Blastula = hollow ball of cells• Blastopore = blastula folds in on itself, creating a

tube– Protostome = mouth is formed by blastopore (eat

and poop from same hole)– Deuterostome = anus is formed by blastopore

(mouth is formed later) (eat and poop from different holes) Ex. echinoderms and all vertebrates.

Cells differentiate into three layers called germ cells.

• Endoderm = inner layer, develops into linings of digestive tract and respiratory system.

• Mesoderm = middle layer which gives rise to muscles and much of the circulatory, reproductive and excretory stystems.

• Ectoderm = outer layer gives rise to sense organs, nerves, and the outer layer of skin.

Radial Symmetry

Bilateral symmetry