Classification is the process of putting things into groups.
Biologists classify living things.
Taxonomy is the grouping and naming organisms.
Dichotomous keys help classify by giving 2 choices.
Species are given a two-part name, the genus and species.
The 5 Kingdoms are Animal, Plant, Fungi, Protist, Monera.
Classifying uses a hierarchical system - kingdom, phylum, class, order, family, genus, species.
Fungi are decomposers, they can’t make their own food e.g. mushrooms and yeast.
Protists are 1-celled organisms e.g. protozoa and algae.
Monera have cells with no nucleus e.g. bacteria.
Vertebrates have a backbone, invertebrates don’t.
Arthropods have an exoskeleton.
Chordates have an internal skeleton, an endoskeleton, e.g. fish, birds, reptiles, mammals or amphibians.
Mammals are placentals, monotremes or marsupials.
Herbivores are organisms that mostly feeds on plants. Herbivores range in size from tiny insects such as aphids to large, lumbering elephants. Herbivores are a major part of the food web, a description of which organisms eat other organisms in the wild.
Omnivores are organisms that eats plants and animals. The term stems from the Latin words omnis, meaning “all or everything,” and vorare, meaning “to devour or eat.” Omnivores play an important part of the food chain, a sequence of organisms that produce energy and nutrients for other organisms.
Carnivores are organisms that eats mostly meat, or the flesh of animals. Sometimes carnivores are called predators.
Classification is a method of organizing plants and animals into categories based on their appearance and the natural relationships between them. Also called scientific classification, it is science's way of identifying and grouping living things. The classification of organisms is a science called taxonomy, or systematics.
Example 1: Australian Vertebrate Land Animals
This dichotomous key uses six criteria.
1. Warm blooded or cold blooded - separates reptiles from mammals
2. Legs or no legs - separates lizards from snakes
3. Feathers or no feathers - separates birds from mammals
4. Casque or no casque - identifies the cassowary (most birds don't have that)
5. Pouch or no pouch - separates marsupials from placental mammals
6. Tail or no tail - identifies the koala
| Common Name | Scientific Name | Characteristics |
|---|---|---|
|
tiger Snake
|
Notechis scutatus | cold blooded, reptile, scales, carnivore, viviparous (does not lay eggs but gives birth to live young), highly venomous, patterned skin, can come in different colours and sizes, no legs |
| goanna (lace monitor lizard) | Varanus varius | cold blooded, reptile, scales, carnivore, lays eggs, long tail, can get up to 2m long, dark grey, 4 legs, sharp claws, can climb trees |
| koala | Phascolarctos cinereus |
warm blooded, marsupial (pouch), fur, herbivore, arboreal (lives in trees), no tail |
| brolga | Antigone rubicunda | warm blooded, bird, lays eggs, feather, large wings, can fly, long beak, long neck, long legs, live in marshland, omnivore |
| cassowary | Casuarius casuarius | warm blooded, bird, lays eggs, feather, casque (strange bone on head), small wings, cannot fly, eats fruits (omnivore), lives in rainforest |
| dingo | Canis dingo | warm blooded, placental mammal (no pouch), carnivore, fur, sharp teeth |
| common brushtail possum | Trichosurus vulpecula | warm blooded, marsupial (pouch), fur, prehensile long tail (can grip branches with tail), mostly folivore (eats leaves) |
If we are to draw out a diagram to demonstrate scientists' methodology, we will construct a multi-level classification system. The rule of the thumb is this: the higher a level is in the animal classification scheme, the more animals it has.
Classification of Living Things
All living organisms are classified into groups based on very basic, shared characteristics. Organisms within each group are then further divided into smaller groups.
Biological Classification is the way scientists use to categorize and organize all of life. It can help to distinguish how similar or different living organisms are to each other.
The pioneer of taxonomy, and of many sciences, was the Greek philosopher Aristotle (384–322 BC). He sought to catalog all known species of animal into higher categories, some of which are still used. His approach was distinctive in its methodology and its ambition. He recognized that not every species could be identified by a single distinguishing feature or characteristic. This permitted him to correctly classify problematic creatures such as the bat, with its anomalous ability to fly among otherwise mammalian features. Aristotle's disciple Theophrastus (c.372–287 BC) extended this method to plants.
Aberdein, A. (2009). Biology: Classification Systems. In K. L. Lerner & B. W. Lerner (Eds.), In Context Series. Scientific Thought: In Context (Vol. 1, pp. 167-176). Detroit, MI: Gale. Retrieved from http://link.galegroup.com/apps/doc/CX3058900029/GVRL?u=61wa_corpus&sid=GVRL&xid=c8fba14d
