The Efficacy of a Practical Activity in the Construction of Knowledge of the Concepts of Species and Phenotypic Plasticity Using the Boldo Mirim (<i>Plectranthus neochilus</i> Schltr.)

Abstract

The analyses efficacy of a practical activity addressing the measure of morphological characteristics of Boldo Mirim (Miniature Boldo), (Plectranthus neochilus Schltr.) which were cultivated in two conditions of solar intensity (50% and 100%), involved two professors and 7 students who participated at different ways in planning, performing and evaluating the results. This activity was carried out in 49 students matriculated in the discipline Botany II of 1st semester of the Biological Sciences course of UFF. The objective of the present study was to foment the construction of a significant learning about concept of specie and phenotypic plasticity. To perform the measurements on the leaves: 1) the foliar areas by two methods (weigh and counting); 2) the internode distance; and 3) the presence of trichome, two types of papers (baking and millimetric) and basic equipment such as manual calibration caliper (mm), precision analytical balance (0.001 g) and a monocular stereoscope (40×) were provided. It was verified that with the reduction in the availability of solar light, the Boldo Mirim increases its leaf area and the distance internodes for the best use of the luminosity in the photosynthetic process, whereas in conditions of full sunshine this plant invests less in leaf area and reduces the distance between leaves that are practically superimposed to avoid stress due to excess of light. After following the proposed protocol, the questionnaire with 12 questions about the plant’s characteristics, the concepts of species and of phenotypic plasticity, and the effectiveness of the practical activity were applied to the 14 groups of 3 to 4 students from the total of 49 ones. The correlation coefficients obtained from the comparison of the two methods used to measure the foliar area (weight and counting) was positive and significant for Branch type 1 (from plant raised at 100% of solar intensity: r = 0.806, n = 10; p ≤ 0.005) and for Branch type 2 (from plant raised at 50% of solar intensity: r = 0.755, n = 10; p ≤ 0.005) as well. These results revealed that the proposal of the practice reached its goals. However, the critics of the 49 target students fell mainly on the restriction of the available time to the practical activity. In conclusion, the activity involvement revealed that the practical activity achieved its purpose. Thus, all the 56 students involved were able to construct the knowledge about the scientific methods, the concepts of species and phenotypic plasticity, and the therapeutic applicability of the Mirim Boldo, within a critical vision of the teaching-learning process.