Lesson Title: Living Clocks
This lesson introduces students to the concept that many of the activities of living things occur in cycles of about 24 hours. The daily cycles are governed by internal "clocks," and internal clocks are cued by the environment but run independently.
• Observe that some behaviors and functions of living organisms vary predictably every 24 hours.
Professional Development Training Module for This Lesson
Lesson Activities and Sequence
Outerspace to Innerspace/Sleep and Daily Rhythms Guide
Living Clocks -- Plant leaf movement, page 6
In this activity students will observe that leaves will be dropped toward the stem very early in the day and fully extended (horizontal) later in the day, regardless of whether the plants are exposed to the sun or artificial light.
Keywords: circadian rhythms, behavior, plants, adaptation
National Science Education Standards, NSTA
• Life cycles of organisms.
Science as Inquiry
• Understanding of scientific concepts.
• Skills necessary to become independent inquirers about the natural world.
Measurement and Data
• Represent and interpret data.