animals notes 1.2 animal symmetrydoc

Notes 1.2 Animal Symmetry
The Mathematics of Symmetry
The bodies of many animals exhibit symmetry, meaning they have a balanced
arrangement of parts.
Three basic types of symmetry…
1) Bilateral Symmetry-The body can only be divided into two halves that look like a mirror
image of one another.
Example: humans
2) Radial Symmetry-There are many lines of symmetry, all of which pass through a
central point.
Example: starfish
3) Asymmetrical-There are no lines of symmetry
Example: Amoeba
Symmetry & Daily Life
Animals with Radial Symmetry
-These animals do not have distinct front and back ends.
-All live in water.
-Most do not move very fast.
Animals with Bilateral Symmetry
-These animals have distinct front and back ends.
-Bodies are streamlined allowing for quick movement.
-Sense organs are usually located on the front end.