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Formal reasoning ability, prior knowledge and abstract achievement in the learning of meiosis and genetics
Author
Sara Zaman
Supervisor
Wan, Yoke Kum
Abstract
The aim of this thesis is to understand the learning of Meiosis and Mendelian genetics by polytechnic students in Singapore, and in particular to identify any misconceptions in these areas that the students may be harbouring. Two strategies were employed in order to investigate this. The first strategy required the construction of a Genetics multiple-choice question (MCQ) test. The 52-item Genetics MCQ test was administered to 75 students as a pre- and post-test. Item analysis indicated that 7 items on the 52-item Genetics MCQ test were either too difficult (Q1), too easy (Q36), or had outlier-sensitive mean square fit statistics (Q18, Q19, Q20, Q29, Q35). Interestingly, analysis of students' responses to Q1 indicated that there existed misconceptions regarding the terminology used to describe chromosome structure (such as chromatid, kinetochore, telomere, and centomere).
The 7 items were removed from the 52-item Genetics MCQ test and the revised 45-item test was administered to 46 students as a pre and post-test. Item analysis indicated that one item was too easy (Q7) and one item had outlier-sensitive mean square fit statistics (Q14). In comparison to the original 52-item Genetics MCQ test, the revised 45-item test was improved in terms of individual item quality. Interestingly, the 52-item test had a slightly higher item reliability (0.93) compared to the 45-item test (0.87). Scores obtained on the Genetics MCQ test corresponded well with the overall grades obtained for the Molecular Genetics module. That is, those students who obtained high scores on the Genetics MCQ test tended to obtain an A grade for the Molecular Genetics module, whereas those students who performed poorly on the Genetics MCQ test tended to also perform overall poorly in the module. Thus, the Genetics MCQ test may be a good predictor for exam performance.
The second strategy required the use of a meiosis template called the Bajema strategy. The Bajema strategy was administered to 121 students and was used to assess whether students understood the cellular processes underlying genetic problem-solving. The Bajema strategy identified 11 major misconceptions that students harboured regarding meiosis and Mendelian genetics. Misconceptions ranged from deduction of incorrect chromosome numbers due to confusion about diploid (2n) and haploid (n) chromosome numbers, faults in chromatid organization, lack of pairing of homologous chromosomes to form bivalents in mid-Prophase I, incorrect arrangement of homologous chromosomes in Metaphase I, mislabeling of chromosomes with allele designations due to poor understanding of what is a chromatid, inability to obtain an alternative genotype pattern of gametes due to the lack of understanding of independent assortment and segregation of chromosomes, and finally the inability to carry out cross-over reactions between alleles.
This study highlights the commonly occurring misconceptions in molecular genetics amongst polytechnic students. Awareness in this area will assist teachers in the development of curriculum (such as in the selection and sequencing of topics) and in their task of guiding students in the construction of correct conceptions. Thus, the identification of students' misconceptions in molecular genetics could lead to significant improvements both in the teaching of molecular genetics and in the students' understanding of this rather challenging subject. With carefully constructed instruction by the educator, the incidence of misconceptions can be reduced, if not eradicated.
The 7 items were removed from the 52-item Genetics MCQ test and the revised 45-item test was administered to 46 students as a pre and post-test. Item analysis indicated that one item was too easy (Q7) and one item had outlier-sensitive mean square fit statistics (Q14). In comparison to the original 52-item Genetics MCQ test, the revised 45-item test was improved in terms of individual item quality. Interestingly, the 52-item test had a slightly higher item reliability (0.93) compared to the 45-item test (0.87). Scores obtained on the Genetics MCQ test corresponded well with the overall grades obtained for the Molecular Genetics module. That is, those students who obtained high scores on the Genetics MCQ test tended to obtain an A grade for the Molecular Genetics module, whereas those students who performed poorly on the Genetics MCQ test tended to also perform overall poorly in the module. Thus, the Genetics MCQ test may be a good predictor for exam performance.
The second strategy required the use of a meiosis template called the Bajema strategy. The Bajema strategy was administered to 121 students and was used to assess whether students understood the cellular processes underlying genetic problem-solving. The Bajema strategy identified 11 major misconceptions that students harboured regarding meiosis and Mendelian genetics. Misconceptions ranged from deduction of incorrect chromosome numbers due to confusion about diploid (2n) and haploid (n) chromosome numbers, faults in chromatid organization, lack of pairing of homologous chromosomes to form bivalents in mid-Prophase I, incorrect arrangement of homologous chromosomes in Metaphase I, mislabeling of chromosomes with allele designations due to poor understanding of what is a chromatid, inability to obtain an alternative genotype pattern of gametes due to the lack of understanding of independent assortment and segregation of chromosomes, and finally the inability to carry out cross-over reactions between alleles.
This study highlights the commonly occurring misconceptions in molecular genetics amongst polytechnic students. Awareness in this area will assist teachers in the development of curriculum (such as in the selection and sequencing of topics) and in their task of guiding students in the construction of correct conceptions. Thus, the identification of students' misconceptions in molecular genetics could lead to significant improvements both in the teaching of molecular genetics and in the students' understanding of this rather challenging subject. With carefully constructed instruction by the educator, the incidence of misconceptions can be reduced, if not eradicated.
Date Issued
2003
Call Number
QH442 Sar
Date Submitted
2003