Problem-solving skills are advantageous when resolving complicated and multidimensional challenges. Problem-solving skills can be developed through active learning models that engage students in the learning process. One active learning model is RICOSRE. The main focus of RICOSRE is problem-solving activities in (1) reading; (2) identifying the problem; (3) constructing the solution; (4) solving the problem; (5) reviewing the solution; and (6) extending the solution. The purpose of this study was to assess the ongoing development of problem-solving skills of students with upper, middle, and lower academic abilities at the Department of Biology Education in a state university in Indonesia. This study employed a concurrent embedded mixed-methods design. The repeated-measures ANOVA was used to test the hypothesis for the quantitative data, and NVivo 12 was utilized to analyze the qualitative data. The participants’ problem-solving skills were determined by their responses to items on RICOSRE-integrated worksheets. The students’ responses were graded using a validated and reliable problem-solving rubric. The findings indicated that the students’ problem-solving skills improved consistently in the upper, middle, and lower academic groups that were taught by implementing RICOSRE.

Critical thinking plays a crucial role in the learning process. Critical thinking should become the focus of learning since it encourages the development of knowledge and includes the act of contemplating subjects, content, and problems. The current study aimed to investigate the effectiveness of Problem-Based Learning (PBL) and Digital Mind Maps-Integrated PBL (DMM-Integrated PBL) in improving students’ critical thinking. This quasi-experiment study employed a pretest-posttest control group design, involving 103 university students from the Biology Department of University in Riau, Indonesia, as the sample. The details of each group consist of 31 students in conventional, PBL (37 students), and DMM-Integrated PBL (35 students) classes. The research data was collected using an essay test. The data obtained were analyzed using ANCOVA at a significance level of 5% and an LSD test. Essay test developed based on critical thinking indicators: basic clarification, bases for a decision, inference, advanced clarification, supposition and integration, and strategies and tactics. All the instruments had been validated. The ANCOVA analysis results proved that PBL and DMM-Integrated PBL affected the students' critical thinking. However, the LSD test showed no significant difference between PBL and DMM-Integrated PBL in promoting students' critical thinking. Finally, to promote students’ critical thinking, educators are recommended to use PBL or DMM-Integrated PBL in the classroom.

Astriani M, Zubaidah S, Abadi AL, Suarsini E. 2020. Pseudomonas plecoglossicida as a novel bacterium for phosphate solubilizing and indole-3-acetic acid-producing from soybean rhizospheric soils of East Java, Indonesia. Biodiversitas 21: 578-586. The use of synthetic fertilizers to grow soybean (Glycine max (L.) Merrill) in a long time, can increase the risk of environmental damage. Therefore, the current study aimed to find phosphate solubilizing bacteria that can produce indole-3-acetic acid (IAA) hormone to minimize the use of chemical fertilizers. Superior isolates selected through characterization of phosphate solubilization activity on Pikovskaya medium, screening of IAA producing bacteria, quantitative estimation of phosphate solubilizing activity using a spectrophotometer, hypersensitivity assay, antagonist within isolate assay, and molecular identification of selected bacterial isolates using 16S rRNA sequencing with primer forward 63f and primer reverse 1387r. Among the isolated bacteria, isolate Arj8 showed the highest phosphate solubilizing activity and IAA production. Molecular identification indicated that isolate Arj8 shared 100% similarity with Pseudomonas plecoglossicida. The highest phosphate solubilizing activity (75.39 mg/L) and IAA production (38.89 ppm) recorded on day-3. Multiple potentialities of P. plecoglossicida as phosphate solubilizing and IAA producing bacterium are a novel finding in the development of bioinoculants as bio-fertilizers that can reduce dependency on synthetic chemical fertilizers.

One of the skills students must possess in the 21st-century biology learning is scientific argumentation skills. Scientific argumentation skills are associated with a strong understanding of concepts and improved critical thinking skills and scientific literacy. The purpose of this study was to investigate the scientific argumentation skills of high school students with different academic abilities. The current study was designed as a survey which involved tenth graders from two public senior schools, SMAN 3 Malang and SMAN 7 Malang. The first served as the representative of students with high academic ability and the latter was appointed to represent the low achievers. The data were analyzed using an independent-samples t-test. The results showed that there were significant differences between the high and ability students’ scientific argumentation skills with a p-value of 0.003. Around 10.34% of the high achievers could perform level 1 argumentation skills, 74.41% of them were able to achieve level 2, and 17.24% of the students reported level 3 responses. Among the students with low academic ability, 12% had reached level 1 argumentation skills and 88% of them were only able to achieve level 2, indicating that no one (0%) could answer the test with level 3 responses. This condition suggests that it is important to implement an innovative learning.