scholarly journals Analizing Student Biology Education Misconception And Scientific Argumentation Ability Using Diagnostic Question Clusters (Dqcs) Of Molecular Genetic Concept

2017 ◽  
Vol 812 ◽  
pp. 012112
Author(s):  
L Nurlaila ◽  
S Sriyati ◽  
Riandi
2018 ◽  
Vol 8 (2) ◽  
pp. 43-53
Author(s):  
Lela Nurlaila ◽  
Siti Sriyati ◽  
Riandi Riandi

This study aimed to analyze the misconceptions and argumentation ability Biology educationstudents using diagnostic question clusters on the concept of molecular genetics. In addition,this study aims to look at the pattern of misconceptions tendencies and scientificargumentation ability of students accompanied by the factors supporting the occurrence ofmisconceptions and arguments student achievement levels. As this study focused on theconcept of molecular genetics which includes the concept of genes, chromosomes, DNA, andprotein synthesis. This research was conducted with the descriptive research method and thesample using purposive sampling techniques. The subjects were biology education students ofIslamic University of Sunan Gunung Djati Bandung who attended the lectures of genetics inthe academic year 2014/2015. The instrument used is a matter of diagnostic question clusters(DQCs) which covers a combined essay and multiple choice questions, learning observationsheet, and interview guidelines used to determine the factors that cause the occurrence ofmisconceptions and what degree of scientific argumentation ability students. The ability of thescientific arguments that will be analyzed is the ability to claim, warrant, backing, andrebutal (Toulmin, 1984).


2021 ◽  
Vol 83 (9) ◽  
pp. 571-574
Author(s):  
Nicholas P. Money ◽  
Mark W. F. Fischer

Cell size is an important variable in the study of cellular growth, metabolism, and the cell cycle. The large size of Amoeba proteus and the ease with which it can be collected and cultured have made it a star in biology education—and it was a model for research on cell biology before the introduction of molecular genetic methods. Measuring the cytoplasmic density of a single amoeba without modern instrumentation seems like a difficult task, but this was done with supreme accuracy in the 1940s. The solution was based on the familiar Cartesian diver that is used to demonstrate Archimedes’s principle. It required the fabrication of a tiny diver that would respond to the additional mass of a cell. Experiments using this method allowed investigators to study changes in size and density associated with feeding, starvation, and cell division. This research is an illustration of the ingenuity of cell biologists in the pre-molecular genetic era of their field, which is often overlooked by contemporary scientists. The consideration of the mass, density, and buoyancy of free-living amoebas encourages a new hypothesis about the evolution of testate amoebas.


2015 ◽  
Vol 54 (03) ◽  
pp. 94-100 ◽  
Author(s):  
P. B. Musholt ◽  
T. J. Musholt

SummaryAim: Thyroid nodules > 1 cm are observed in about 12% of unselected adult employees aged 18–65 years screened by ultrasound scan (40). While intensive ultrasound screening leads to early detection of thyroid diseases, the determination of benign or malignant behaviour remains uncertain and may trigger anxieties in many patients and their physicians. A considerable number of thyroid resections are consecutively performed due to suspicion of malignancy in the detected nodes. Fine needle aspiration biopsy (FNAB) has been recommended for the assessment of thyroid nodules to facilitate detection of thyroid carcinomas but also to rule out malignancy and thereby avoid unnecessary thyroid resections. However, cytology results are dependent on experience of the respective cytologist and unfortunately inconclusive in many cases. Methods: Molecular genetic markers are already used nowadays to enhance sensitivity and specificity of FNAB cytology in some centers in Germany. The most clinically relevant molecular genetic markers as pre-operative diagnostic tools and the clinical implications for the intraoperative and postoperative management were reviewed. Results: Molecular genetic markers predominantly focus on the preoperative detection of thyroid malignancies rather than the exclusion of thyroid carcinomas. While some centers routinely assess FNABs, other centers concentrate on FNABs with cytology results of follicular neoplasia or suspicion of thyroid carcinoma. Predominantly mutations of BRAF, RET/PTC, RAS, and PAX8/PPARγ or expression of miRNAs are analyzed. However, only the detection of BRAF mutations predicts the presence of (papillary) thyroid malignancy with almost 98% probability, indicating necessity of oncologic thyroid resections irrespective of the cytology result. Other genetic alterations are associated with thyroid malignancy with varying frequency and achieve less impact on the clinical management. Conclusion: Molecular genetic analysis of FNABs is increasingly performed in Germany. Standardization, quality controls, and validation of various methods need to be implemented in the near future to be able to compare the results. With increasing knowledge about the impact of genetic alterations on the prognosis of thyroid carcinomas, recommendations have to be defined that may lead to individually optimized treatment strategies.


2010 ◽  
Vol 30 (S 01) ◽  
pp. S153-S155
Author(s):  
D. Delev ◽  
S. Pahl ◽  
J. Driesen ◽  
H. Brondke ◽  
J. Oldenburg ◽  
...  

1995 ◽  
Vol 73 (05) ◽  
pp. 756-762 ◽  
Author(s):  
Yoshiaki Tomiyama ◽  
Hirokazu Kashiwagi ◽  
Satoru Kosugi ◽  
Masamichi Shiraga ◽  
Yoshio Kanayama ◽  
...  

SummaryWe analyzed the molecular genetic defect responsible for type I Glanzmann’s thrombasthenia in a Japanese patient. In an immunoblot assay using polyclonal anti-GPIIb-IIIa antibodies, some GPIIIa (15% of normal amount) could be detected in the patient’s platelets, whereas GPIIb could not (<2% of normal amount). Nucleotide sequence analysis of platelet GPIIb mRNA-derived polymerase chain reaction (PCR) products revealed that patient’s GPIIb cDNA had a 75-bp deletion in the 3’ boundary of exon 17 resulting in an in-frame deletion of 25 amino acids. DNA analysis and family study revealed that the patient was a compound heterozygote of two GPIIb gene defects. One allele derived from her father was not expressed in platelets, and the other allele derived from her mother had a 9644C → T mutation which was located at the position -3 of the splice donor junction of exon 17 and resulted in a termination codon (TGA). Moreover, quantitative analysis demonstrated that the amount of the abnormal GPIIb transcript in the patient’s platelets was markedly reduced. Thus, the C → T mutation resulting in the abnormal splicing of GPIIb transcript and the reduction in its amount is responsible for Glanzmann’s thrombasthenia.


1997 ◽  
Vol 77 (02) ◽  
pp. 238-242 ◽  
Author(s):  
J Oldenburg ◽  
J K Picard ◽  
R Schwaab ◽  
H H Brackmann ◽  
E G D Tuddenham ◽  
...  

SummaryMolecular genetic studies have shown that development of antibodies to factor VIII (inhibitors) occurs most frequently in patients with severe haemophilia due to major gene lesions including inversions, stop codons and large deletions. Previous studies of HLA type were performed on inhibitor and non-inhibitor patients with diverse uncharacterised mutations which may have confounded detection of significant associations. We therefore selected a group of patients with a single mutation type, the prevalent intron 22 inversion, with or without inhibitors, to determine HLA genotype. Seventy-one such patients, 42 without and 29 with inhibitors (13 high, 9 low and 7 transient responders) were genotyped for MHC Class I HLA-A, -B, -C and Class II HLA-DQA, -DQB and -DRB loci. No strong correlation of any HLA-allele to inhibitor or non-inhibitor status was found. However, alleles of the haplotype HLA-A3, HLA-B7, HLA-C7, HLA-DQA0102, HLA-DQB0602, HLA-DR15 occurred more often in inhibitor patients. Since the alleles of this extended haplotype are common in the North European population only a very strong association would achieve statistical significance. Further studies of groups of patients similar to those studied here will be needed to confirm or exclude this association.


1996 ◽  
Vol 16 (02) ◽  
pp. 114-138 ◽  
Author(s):  
R. E. Scharf

SummarySpecific membrane glycoproteins (GP) expressed by the megakaryocyte-platelet system, including GPIa-lla, GPIb-V-IX, GPIIb-llla, and GPIV are involved in mediat-ing platelet adhesion to the subendothelial matrix. Among these glycoproteins, GPIIb-llla plays a pivotal role since platelet aggregation is exclusively mediated by this receptor and its interaction with soluble macromolecular proteins. Inherited defects of the GPIIb-llla or GPIb-V-IX receptor complexes are associated with bleeding disorders, known as Glanzmann's thrombasthenia, Bernard-Soulier syndrome, or platelet-type von Willebrand's disease, respectively. Using immuno-chemical and molecular biology techniques, rapid advances in our understanding of the molecular genetic basis of these disorders have been made during the last few years. Moreover, analyses of patients with congenital platelet membrane glycoprotein abnormalities have provided valuable insights into molecular mechanisms that are required for structural and functional integrity, normal biosynthesis of the glycoprotein complexes and coordinated membrane expression of their constituents. The present article reviews the current state of knowledge of the major membrane glycoproteins in health and disease. The spectrum of clinical bleeding manifestations and established diagnostic criteria for each of these dis-orders are summarized. In particular, the variety of molecular defects that have been identified so far and their genetic basis will be discussed.


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