March 6, 2002
Evaluate insect classification and diversity
Web posted at: 12:41 PM EST (1741 GMT)
Overview: CNN Student News correspondent Michael McManus interviews Dr. David Furth about classification and identification of insects. Examine the classification process used for insects. Have students use dichotomous keys to identify unknown insects.
Curriculum connections: Biology, Life science
ObjectivesExplain the classification process used for insects.
Use dichotomous keys to identify insects.
Students will be able to:
National Science Education Standards
Life science, Standard C, grades nine –12
Students should know that biological classifications are based on how organisms are related. Organisms are classified into a hierarchy of groups and subgroups based on similarities which reflect their evolutionary relationships. Species is the most fundamental unit of classification.
Living environment, Diversity of life, grades nine –12
Students should know that the degree of kinship between organisms or species can be estimated from the similarity of their DNA sequences, which often closely matches their classification based on anatomical similarities.
CNN Student News story, ""Insect classification and diversity"
Variety of shoes
Pictures of various insects
glossary from Holt, Rinehart and Winston
Article and questions only: 30 minutes
Full lesson plan: Two to three classroom periods
1. Display a variety of shoes to the class. Ask students for their ideas on ways to put the shoes into groups. For each grouping, record the defining characteristic and the shoes that belong in the group. Identify shoes that fit in more than one grouping. Ask: How might putting objects into groups be helpful? What do you think are some other possible ways to group the shoes? Discuss. Inform students that classification is the arrangement of organisms into orderly groups based on their similarities. Then, ask: Why do you think scientists classify insects? Explain.
2. Have students read the CNN Student News ""Insect classification and diversity", story and ask the following:
Who is David Furth? What is his occupation and where does he work? What are some of his job responsibilities at the Smithsonian Museum of Natural History? What is his favorite bug? How does Furth describe the predatory ground beetle?
Why do you think Furth compares categorizing species to a family tree? What is meant by the term "taxonomy"? What taxonomy classifications does he mention? What is the relationship among phylum, class and order?
In what language are species given names? What variables are utilized in the classification process? Why do you think there are very strict rules and standards used when classifying and organizing insects? What other information about insects does Dr. Furth mention that is beneficial to scientists?
3. Inform students that Holt, Rinehart and Winston defines a dichotomous key as an "aid to identify unknown organisms that consist of several pairs of descriptive statements; of each pair of statements, only one will apply to the unknown organism, and that statement will lead to another set of statements, and so on, until the unknown organism can be identified." Give each student a picture of an unknown insect, such as a cicada, ladybird beetle, katydid, bumblebee, butterfly, dragonfly or wasp. Refer students to the first Web site below for a dichotomous key to identify their insects. Invite students to share their experiences using dichotomous keys.
Direct each student to prepare a written analysis of the following statement: "All bugs are insects, but not all insects are bugs." Have students share their responses. Then, ask: What are some common examples of animals that are often confused with insects? Why do you think many people think spiders are insects? Discuss.
Have students create cartoons that show how using different common names for an insect instead of its scientific name can create confusion. Students must include authentic common names and their scientific names in their cartoons. Have students share their cartoons with the class.