Animal Kingdom Basics

Body Areas

Head

Back

Tail end

Belly

Symmetry: Arrangement of the body parts around a central axis

Asymmetry

Body that cannot be divided into equal

parts

Radial Symmetry

Body arranged around a central axis

Bilateral Symmetry

Body that can be divided into equal

halves

Identify the following examples of symmetry as asymmetrical, radial, or

bilateral

External Segmentation

Segments located on the outside of the body

Internal Segmentation

Segments located on the inside of the body

Skeletal SystemProvides structure and support for animals

ExoskeletonSkeleton on the outside of the body;

external skeleton

*

EndoskeletonSkeleton on the inside of the body;

internal skeleton

Hydrostatic skeletonFluid-filled cavity surrounded by muscles;

fluid provides support

Digestive SystemBreaks down food into energy

Two-way Digestion*

One opening;

food goes in out the same

opening; moves in two

directions

One-way Digestion

Two openings; Food goes in the “mouth” and out the “anus”; moves in one direction

Circulatory SystemTransports oxygen throughout an organism

Closed Circulatory SystemBlood moves throughout an organism closed

within blood vessels

Open Circulatory System

“Blood” moves openly

throughout an

organism; No vessels

Respiratory SystemExchange gases; Oxygen is taken in and

Carbon Dioxide is released.

Diffusion

Oxygen moves across a thin membrane; carbon dioxide is release

Feather-like structures that take in dissolved oxygen from aquatic

environments; releases carbon dioxide

Gills

Lungs

Organ found in animals that take in oxygen from

the atmosphere; releases carbon

dioxide

Nervous SystemTransmits signals throughout an organism;

allows a response to a stimulus

Nerve Net

Net of nerves that spreads throughout an organism; lacks a control center

Nerve CellControl center; nerve cords extend

throughout body; receive and carry messages

IntegumentOutermost layer of an animal; functions in protection from dehydration, freezing, etc.

Excretory SystemGets rid of waste in an organism

Reproductive SystemProduces offspring

BuddingOffspring grows from parent; Asexual

reproduction; Identical to parent

Fragmentation

An organism is broken into pieces; the pieces grow into a new organism

Hermaphrodite

Both sexes are present; produce sperm/egg

External FertilizationUnion of the egg and sperm outside of the

organism

Internal FertilizationUnion of egg and sperm on the inside of an

organism