Activity 5: Activity Overview

Students observe the difference in the growth of plants when the plants must compete for space and nutrients. They also observe what happens when different species compete. They then design and carry out an experiment to study competition under different conditions.

Preparation and Materials Needed
Preparation
You and the students will need to set up Part A of this activity at least three weeks ahead of the time that you are ready to discuss competition. Students will be making and recording observations approximately every two days during the three weeks. You do not need to discuss the importance of competition prior to planting the seeds. Students will still be able to make meaningful observations. Leave the What Do You Think? questions until you are ready to teach the lesson.

You may also wish to set up Part B in advance. However, it would also be appropriate for students to do this part of the activity as an extension. Discussion of adaptations continues in the following chapter on evolution and experimental results would be equally meaningful at that time.

Materials/Equipment Needed (per group)

• 6 milk container bases (or similar containers)
• potting soil
• cress seeds (about 80)
• lettuce seeds (about 15)
• variety of other seeds (students’ choice)
• small watering can (or suitable substitute)
• ruler