Sajidan

Enhancing High School Students's Rebuttals as An Important Aspect of Scientific Argumentation Skill Through Problem Based Learning

Rebuttal is an essential aspect in scientific argumentation skill. Level of scientific argumentation skill depends on the quality of the rebuttal process. Students who can produce a high-quality rebuttal to defend their claims are proved higher level of scientific argumentation skill than the student who can only produce claims, evidence and reasoning. Problem-based learning (PBL) is a learning model that provides real life ill-structured problem, that need to be solved through investigation and discussion. It is able to help students to enhance their rebuttal skill. This research was aimed to analyze the rebuttal improvement process by applying PBL based module in 10th-grade student of SMAN 1 Punung. This research was an evaluation stage from our R&D research using pretest-post test control-experiment group design. Data were collected using test, interview, and classroom observation. The result showed that the students rebuttals in the experimental group increase up to 27,27%. The t-test result also indicated different significant result between pretest and posttest scores. Based on the research result can be concluded, that by implementing PBL based model in the10th-grade senior high school is able to improve students rebuttal skill.

Morphological characteristics and isozyme banding patterns of Cucurbita moschata at different altitudes

Hidayati NR, Suranto, Sajidan. 2018. Morphological characteristics and isozyme banding patterns of Cucurbita moschata at different altitudes. Biodiversitas 19: 1683-1689. Aims of this research were to investigate the morphological character and isozyme banding patterns of Cucurbita moschata plants grown at three different altitudes. Samples in this study consisted of leaf, stem, and flowers. The morphological characters were conducted by direct observation in the field and analyzed descriptively as well as statically by one way ANOVA. The isozyme bands appearance of esterase and peroxidase of leaf samples were conducted using polyacrylamide gel electrophoresis (PAGE). Qualitative approach was used to analyze the presence and the absence of isozyme bands, while Retardation factor (Rf) was used to analyze quantitatively. The results showed that most plants grown at middle altitude (351-750 m asl.) were well-developed in terms of length of leaves, stems and flowers. Accordingly, the isozyme banding pattern of peroxidase was also found varied in plants grown at middle altitudes from which the presence of very unique bands was detected. Conversely, the band detected in plants grown at the lower and the highest altitudes was similar in term of bands number but it was different in the quality of the bands. Meanwhile, esterase isozyme banding pattern of plants grown at the lower and higher altitude had more bands than the middle altitude. Based on this result it is obvious that the isozyme data could be used to support in understanding the diversity morphological characters of plants grown in three different altitudes. This early result suggests that altitudes as a crucial factor in contributing the expression of isozyme appearance, which is useful for further pumpkin characterizations.