A dichotomous key is important because of the sheer amount of species on Earth. Currently, there are 1.5 million species on the planet, and there may be up to 100 million more than have been undiscovered.

A dichotomous key will consist of a series of questions, usually about a specific species. When a user answers one question, the key helps the user decide what question to ask next to finally arrive at an answer. There will always be two answers to a question, making it easier for the user to get to the final answer and identify the unknown organism or object. Many will have “yes” or “no” as the two answers.

If the key is about a certain species, the scientific name for the species will be used. This is because the common names used for species usually refer to various species that simply look similar to one another.

For example, a moth and a butterfly look similar, but the fact is that they are completely different. They are both part of the scientific order Lepidoptera, but they serve different functions in the world and have many dissimilar traits. Having the scientific name will clear up any confusion.

For this assignment you will create a dichotomous key to help you Identify Bacteria (which are a pain in the bum to identify on the species level.) We will be focused on the general terms of bacteria and the only Phylum that will be addressed is the Cyanobacteria.

Use the following to create a dichotomous key to begin to identify Bacteria:

BACTERIA

Bacillus

Coccus

Spirillium

Phylum Cyanobacteria

.Gram (+) (-)

Root nodules

To Begin use the following question:

Does the organism exhibit a membrane bound nucleus?