Student Understanding of Osmosis and Water Potential: A case study Tor Siong Hoon Pahang Matriculation College

Objectives of Study explore student learning difficulty in osmosis and water potential identify level of student understanding in osmosis and water potential.

Significance of the Study concept of water potential gaseous exchange and control in plants transport of water and minerals in plants.

Limitation of Study 93 life science students taught by 2 lecturers from biology tutorial classes studying biology in the Bahasa Malaysia at secondary school level. students in matriculation program for about two months focused on osmosis and water potential

Research design Benjamin Bloom (1964) three domains: cognitive, affective and psychomotor in educational activities six major categories: starting from the simplest behavior to the most complex Knowledge Comprehension Application Analysis Synthesis Evaluation

Independent Variables Research design Independent Variables Dependent Variable Understanding definitions of terms Explaining, illustrating concepts & evaluation Understanding Water Potential Understanding Water Potential Application of concepts

Methodology of Study quantitative and qualitative approaches of data collection. quantitative data: diagnostic test related to the learning water potential based on the guide of Bloom’s taxonomy ranging from knowledge, comprehension, application, analysis, synthesis and evaluation. quantitative method: self evaluation form based on the diagnostic test

Data Analysis Reliability analysis for internal consistency using Cronbach alpha yielded a coefficient of 0.691 Factors Number of items Cronbach alpha A: Definition 8 0.760 B: Explain 2 0.658 C: Illustrate & Predict 12 0.666 D: Problem Solving 5 0.672

Findings SPM Results (%) A1 & A2 B3 & B4 C5 & C6 Biology 28.0% 60.2%   SPM Results (%) Count A1 & A2 B3 & B4 C5 & C6 Biology 28.0% 60.2% 10.8% 93 Chemistry 40.9% 48.4% Physics 22.0% 49.3% 28.6% 91 Mathematics 98.8% 2.2% 1.1% English 41.9% 49.5% 8.6%

Osmosis & isotonic solutions Hypertonic and hypotonic solutions Concentration gradient, water potential, solute potential, and pressure potential

membrane is selectively permeable membrane is selectively permeable to water and iodine

Figure 3 Figure 4

C: Illustrations of Concepts Figure 4 (isotonic solutions) better understood compared to figure 3 (solutions of different concentrations) Confusion probably arises as a result of the basic concept of osmosis not well understood. consistent with the trend as in section A more students could define isotonic solutions but lesser students could define hypertonic

D: Making evaluations Refer to figure 4, state whether: Correct Wrong Not answered Count & Percentage i. there is water movement between 2 isotonic solutions 70 (75.3%) 21 (22.6%) 2 (2.2%) ii. there is net water movement between 2 isotonic solutions 39 (41.9%) 43 (46.2%) 11 (11.8%) iii. there is net change in water concentration on either side of membrane 38 (40.9%) .45 (48.4%) 10 (10.8%)

D: Making evaluations higher level of understanding 75.3% for 2 isotonic solutions. 41.9% for net water movement. students seem to either guess or they do not really understand what happens to the water molecules in isotonic solution.

E: Problem Solving The water potential of a plant cell (cell) can be calculated using the following equation. cell = s +  where s = solute potential and p = pressure potential A plant cell was immersed in pure water until it was fully turgid (shown in figure 5). It was then placed in a concentrated solution until it was plasmolysed. The table shows some of the values of the potentials in the cell at equilibrium under these different conditions. Figure 5 Condition of cell Potential (kPa) cell s p fully turgid (i) (ii) +350 plasmolysed (iii) -550 (iv)

E: Problem Solving Cell when fully turgid, 61.3% of the students answered correctly the skill involved is mechanical formula substitution. Cell in a different condition (plasmolysed) 47.3% of the students answered correctly skill involve demands understanding of solute potential, pressure potential to calculate water potential

Suggestions Silverman (1987): student’s learning governed by student’s native ability and prior preparation. also depends on learning style and instructor’s teaching style Felder (2005): students have different levels of motivation and different responses to specific classroom environments and instructional practices Woods et al. (2000): students who adopted a strategic approach of study are more organized and efficient in their study

Suggestions … contd Yusminah et al. (2006) found that most of the Biology lecturers merely read the slides during lecture classes. Suggestion in this study: Although not possible to discover everything that affects what a student learns in a class, needful for the lecturers at Matriculation to explore and devise varied teaching strategies to induce students to adopt a deep approach to learning and promote students’ intellectual development

Conclusion Basic concepts taught in their secondary schools not fully understood Students could not master questions in higher learning levels because they have not mastered lower learning skills parallel to the idea posed by in the Bloom’s Taxonomy Students rely on rote memorization and mechanical formula substitution make little or no effort to understand the material being taught. Students have not really explored the limits of applicability of new material only skiing through the concepts on water potential.

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