Characteristics of Animals

�         The Animal kingdom is the largest of the five kingdoms

�         They are multicellular and eucaryotic organisms

They are heterotrophic organisms
- They are motile organisms and have developed a muscular and nervous system for this purpose

�         Most  of them reproduce sexually

�         Some simpler animals reproduce asexually 

�         In some animals the young
   have the basic features as
   the adults

The others, the young are very different from adults    The young forms are
    known  as larvae

Symmetry in Animals

The body of most animals show    symmetry

Symmetry: The body can be     cut into two halves that have    matching shapes.

Radial Symmetry. An adult starfish shows radial symmetry

Bilateral Symmetry.Frogs, like humans, show bilateral symmetry. There is only one way to cut the organism into two symmetrical halves.

A few organisms are asymmetry amebas and  most sponges

Asymmetry: There is no way that the organism can be cut into two matching halves

More than  90 percent of all animal species  are  invertebrates

Animals are classified in to two large groups
               * Invertebrates
               * Vertebrates

Invertebrates: Animals without    a backbone

Vertebrates : -Animals with   a backbone