To make a dichotomous key
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The word dichotomous comes from two Greek words that mean divide in two parts. To make a dichotomous key you will choose physical characteristics that can be used to divide a collection into two parts. Possible physical characteristics to use include plant size, plant shape, leaf shape, stem type, color, and presence of seeds, fruits or flowers. You will continue to divide each group in two until all of the groups have only one member.
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The Process
Step 1: Begin by gathering your plants (or pictures of plants) to be identified. For example: a corn plant, hosta, oak tree and dandelion.
Step 2: Decide how to split your group in two parts. Carefully observe your specimens to pick a characteristic which can be used to decide which plant goes into which group. Record the chosen characteristic and the groups formed.
Step 3: After the collection has been divided into two groups, divide the first group (group A) into two more groups based on one characteristic. Record your characteristic and groups. When you form a group with only one plant, name it.
Step 4: Continue to identify characteristics and divide groups until all of the plants are named. Be sure to record each division made. When the first group is complete, repeat the steps until all of the plants in the second group (group B) have been named.
Dichotomous Tree Identification Key
A dichotomous key is a scientific tool
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A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish.
By observing similarities and differences in plants, scientists can classify plants into families and gain further understanding of their characteristics. Scientists use dichotomous keys to organize and classify large amounts of information so it can be easily shared with other scientists and studied.Dichotomous keys can be developed to identify anything.
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Keys consist of a series of choices that lead the user to the correct name of a given item. "Dichotomous" means "divided into two parts". Therefore, dichotomous keys always give two choices in each step.