Cycles of Nature

This is an online introduction to Chronobiology based on the book Cycles of Nature. Successive segments build on each other. Material is suitable for middle- or high-school age students.

Begin Intro to Biological Rhythms -->

Introduction

The Difficulties in Seeing Cycles

Cycles in Plants and Animals

The Role of Environmental Influences

The Role of Internal Influences

The Role of Cycles in the Body

Ahlgren A., Halberg F.: Cycles of Nature: An Introduction to Biological Rhythms - National Science Teachers Association, Washington, DC. 1990, 87 pp.