Arizona Hedgehog Cactus: Lesson 1

Lesson 1: Presentation of the Problem

Purpose: To introduce the students to the research question through a slide show, overhead transparency and discussion.

Time: One 50-60 minute class period

Materials Preparation:

Computer and internet access (individual computers or projection mechanism)

Overhead transparency of "Possible Phylogeny and Ploidy Levels of Claret-Cup Cacti"

Student copies of "The Arizona Hedgehog Cactus: Endangered Species or Not?"

Student copies of "Classification of Echinocereus triglochidiatus and Geographical Ranges of its Varieties".

Student Objectives:

List the morphological characters used to identify the cacti in the field, and describe the associated problems in using these characters for identification.

Draw the geographical ranges of the varieties of species Echinocereus triglochidiatus.

Lesson Plan:

(1) Present slides in the order given. Refer to "Investigation of the Problem- Internet Slide Show". A narration is included. Students may view the slide show in small groups or, if a multimedia hookup is available, the slide show may be projected through the computer onto a class television.

(2) Students complete the activity sheet entitled "Investigation of the Problem" as they watch and listen to the slide presentation.

(3) Present the research question to the class: Are the cacti in Cochise county similar enough to the cacti at the type locality of arizonicus to be considered the same variety? Hand out background reading material, "The Arizona Hedgehog Cactus: Endangered Species or Not?" Hand out and explain the homework assignment, "Classification of Echinocereus triglochidiatus and Geographical Ranges of its Varieties."

Supplemental Materials:

"Investigation of the Problem: Internet Slide Show" - Slide Show
"Investigation of the Problem" - Worksheet
"The Arizona Hedgehog Cactus: Endangered Species or Not?" - Background Reading
"Possible Phylogeny and Ploidy Levels of Claret-Cup Cacti" - Overhead Transparency
"Classification of Echinocereus triglochidiatus and Geographical Ranges of its Varieties" - Worksheet
"Classification of Echinocereus triglochidiatus and Geographical Ranges of its Varieties" - Answer Key