The document is about a dichotomous key, which is a written tool used to identify plants and animals. It consists of a series of paired questions that leads the user down different paths through a sequence of choices until an identification is reached. Each choice directs the user to the next question couplet number to follow. Dichotomous keys break down classifications into a step-by-step process.

1. Dichotomous Key

2. How can you tell ...

3. How can you tell ...

4. How can you tell ...
cc licensed flickr photo by Gerald Yuvallos: http://flickr.com/photos/gyuvallos/

5. How can you tell ...
cc licensed flickr photo by Gerald Yuvallos: http://flickr.com/photos/gyuvallos/
cc licensed flickr photo by Max xx: http://flickr.com/photos/max_westby/54275159/

6. How can you tell ...

7. How can you tell ...
cc licensed flickr photo by squacco: http://flickr.com/photos/squeakywheel/

8. How can you tell ...
cc licensed flickr photo by rob.wall: http://flickr.com/photos/robwall/4126397372/
cc licensed flickr photo by squacco: http://flickr.com/photos/squeakywheel/

9. How can you tell ...

10. cc licensed flickr photo by Vic DeLeon: http://flickr.com/photos/hdude/
How can you tell ...

11. cc licensed flickr photo by Vic DeLeon: http://flickr.com/photos/hdude/
cc licensed flickr photo by yeimaya: http://flickr.com/photos/yeimaya/539411643/
How can you tell ...

12. How can you tell ...

13. cc licensed flickr photo by Martin_Heigan: http://flickr.com/photos/martin_heigan/2006285937/
How can you tell ...

14. cc licensed flickr photo by Martin_Heigan: http://flickr.com/photos/martin_heigan/2006285937/
How can you tell ...
cc licensed flickr photo by Martin LaBar (going on hiatus):
http://flickr.com/photos/martinlabar/2739969169/

15. A dichotomous key

16. A dichotomous key
A written tool for identification of plants and
animals. It is written as a sequence of paired
questions, the choice of which determines the
next pair of questions until a name or
identification is reached.

18. The number indicates which
couplet to go to next.