As microalgas e a vida: o micromundo fotossintetizante e alunos de ensino médio

Abstract

Microalgae, microscopic prokaryotic or eukaryotic organisms that perform photosynthesis, can be found freely in the water column or associated with the roots of aquatic macrophytes, forming the periphyton. Periphytic microalgae play an important role in the stabilization of aquatic ecosystems. However, despite their relevance, microalgae are little known by high school students, who end up showing a lack of interest in the disciplines of Botany. This lack of interest may be related to the difficulties faced by teachers when preparing practical classes, such as the lack of equipment, and to the mechanized teaching model, which only exposes the content. Therefore, this work aimed to bring knowledge about microalgae to high school students in a public school, so that they could learn the content relating these organisms to their daily experiences. For the study, we used aquatic plants of the species Salvinia auriculata, Pistia stratiotes and Eichhornia crassipes. Two meetings were held between the team at the Federal University of Lavras and the students from the first year of high school at the Cinira Carvalho State School in the city of Lavras - MG. At the first meeting, the students handled the aquatic plants, and we stimulated a discussion with them about these organisms, the periphytic microalgae and the importance of the conservation of aquatic ecosystems. In the second meeting, we explored further the knowledge about microalgae and macrophytes. Also, we instructed the students to prepare slides containing periphytic microalgae and view them under the optical microscope. During the first meeting, we were already able to perceive a great interest from the students. Although some know the plants, the new information combined with the experiences and the possibility of touching the plants made the students participate more actively in the class and question the life and the environment where aquatic plants lived. During the second meeting, the students were even more excited after preparing their slides and viewing the algae present in them. We also noticed, during the second meeting, that the students showed more mastery about the topics covered in the first meeting. Thus, considering the results observed, we reinforce the importance of allowing students to share their personal experiences related to the topic studied, and of university extension activities as an effective way of disseminating science.