(1) Animals which have a single cell body performing all functions, are called unicellular animals,
e.g. Amoeba
(2) Animals which have many cells in their body, are called multicellular animals,
e.g. Cat
(3) Animals with vertebral column are called vertebrates,
e.g. Man
(4) Animals without vertebrate column are called invertebrate animals,
e.g. Earthworm
(5) Animals which lay eggs and hatch them are called oviparous animals,
e.g. Hen
(6) Animals which give birth to their young ones are called viviparous animals,
e.g. Dog