Dichotomous Key

This e-book can help with the identification of unknown organisms or species. The method adopted uses mostly a dichotomous key based on two choices, which is either in written format or pictographic, or both. For convenience, there may be polytomous sections within the book.

A written dichotomous key presents the reader with two statements that describe certain characteristics. The statements should be mutually exclusive for the key to work efficiently. For example, 'it is either red or it isn't'. On selecting one, the reader is presented with the next couplet choice in the key and so on - to eventually arrive at an identification. This key uses hyperlinks to navigate.

Classification with keys

Taxonomic systems are based on similar characteristics or increasingly on DNA analysis. The systems attempt to model the natural order, thus helping research by classifying different organisms. Taxonomic systems vary, but the following system has been found useful:

There are many sub units in use.

Keys usually start with a first selection from the following:

How the key works

  1. Go to start
  2. Use choices given to arrive at the lowest possible level
  3. Organism is identified as much as possible


If the description at each level does not appear accurate then back up to some earlier couplet and start over, questioning each decision more carefully. Finally, a verification step is important by comparing the specimen with any further details available including description,photographs and other reference. The habitat and location where the sample was collected is useful for plants. If the description and other information satisfactorily confer, then a correct identification is possible.

Start Here

Which Kingdom does it belong to?

Animalia

How many legs does it have

Plantae

What kind of plant is it?

No legs

What kind of animal is it?

2 Legs

What kind of animal is it?

4 Legs

What kind of animal is it?

Many legs

What kind of animal is it?

Fish

What kind of fish is it?

(Osteichthyes): Actinopterygii & Sarcopterygii, but also lampreys (Myxini) and hagfish (Petromyzontida)

Bird

What kind of bird is it?

Insect

What kind of insect is it?

Mammal

What kind of mammal is it?

Mammalia

Lizard

What kind of lizard is it?

==Shark

The keys in Wikibooks are still under development. A raw list is given below:

This article is issued from Wikibooks. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.