Module 3 Intro

Module 3—Ecosystems and Their Diversity

Read

From your work in Lesson 2, you should be able to classify organisms into their domains and kingdoms based on cellular characteristics. In this lesson you will learn to use characteristics based on morphology to identify organisms.

Read page 89 in your textbook, and look at the structure of “Table 3.2.” This key will help you to make more specific classifications of an organism based on observable characteristics.

One way to identify different species is to use a dichotomous key. A dichotomous key is a series of yes and no questions that lead to the identification of a species. Questions in a dichotomous key refer to observable characteristics that can be used to identify an organism at the genus species level. This is the italicized Latin name that is recognized by scientists worldwide.

Try This

TR 1. Dichotomous keys can also be created in an electronic format. Try using the following examples for practice and to see how dichotomous keys are structured. The next Try This question will require you to create your own dichotomous key.

Use an electronic dichotomous key to identify Alberta wildflowers. The animation uses the flower colour and structure to classify the wildflowers. Try identifying four different flowers. You have correctly identified the flower if you receive a .

Now try identifying plants with dichotomous keys by using another website. To find this web activity, type the keywords “world web wonders dichotomous key” into a search engine. The first link that appears should be the link to the correct activity. If you wish, you may try other sites that you find in your search.

TR 2. Creating a Dichotomous Key

In this activity you will be completing “Investigation 3.B: Creating a Dichotomous Key” on page 90 in the textbook. To give you an idea of how to create a dichotomous key, read the example page on “How to Make a Dichotomous Key for Shoes.”

Proceed to Module 3: Lesson 3 Assignment to complete this activity.

Self-Check

SC 1. Answer question 5. a) and b) on page 92 of your textbook.

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