All life forms, from amoebas to zebras, and even your younger
brother, have nine basic functions in common. These are:
| Nutrition |
Transport |
| Respiration |
Excretion |
| Synthesis |
Regulation |
| Growth/Development |
Reproduction |
| Responsiveness/Adaptability |
|
In addition to these functions, life forms
have certain other things in common, such as cells which form the
structure of almost all living things, and the chemical compounds
found in living matter which encompass both inorganic and organic
compounds. The organic compounds include carbohydrates, lipids,
proteins, and nucleic acids.
Don't Worry, You're Different
Too
While you do have a lot in common with
bacteria and fungus, life forms are classified according to their
differences in structural, developmental, and evolutionary
relationships. The criteria for classification in different
kingdoms are: presence or absence of a nucleus or other
membrane-bound organelles; unicellularity or multicellularity;
mode of nutrition; and method of reproduction.
But there are huge differences even within
the same kingdom. For instance, some phyla in the Kingdom Animal
are coelenterates, echinoderms, and chordates. Coelenterates
include animals with two cell layers and tentacles to gather and
ingest food, like jellyfish. Echinoderms have 5-fold radial
symmetry, sucker feet, and hydroskeletons, like starfish.
Chordates, on the other hand, have a dorsal nerve chord
(vertebrates have dorsal support as well) and have endoskeletons,
like sharks and humans.
So while you might have more genes in
common with your siblings than you might desire, no one will
confuse you with an amoeba... yet.
Now you try it...
