The Zimbabwe Secondary School Science Project (ZIM-SCI) developed student study guides, corresponding teaching guides, and science kits for a low-cost science course which could be taught during the first 2 years of secondary school without the aid of qualified teachers and conventional laboratories. This teaching guide contains instructional strategies for exercises which consist essentially of observing and recording changes in the development of organisms. These exercises provide the practical background to concepts presented in the ZIM-SCI units E1 ("Life: Beginning and Growing") and E2 ("Reproducing by Flowers and Seeds"). Although methods to study the development of the frog, mosquito, housefly, bean, and maize are provided, similar methods may be applied to other organisms of choice (depending on time of year and organisms available in a given area). Since no student study guide accompanies this teaching guide, it is strongly recommended that unit be read before starting and that exercises be presented in the order in which they appear. (JN)