• Title/Summary/Keyword: evolution and genetics

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Pre-service Science Teachers' Perceptions of Significance and Usefulness of Evolution and Genetics (예비과학교사들의 진화와 유전에 대한 중요성과 유용성에 대한 인식)

  • Ha, Minsu
    • Journal of Science Education
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    • v.40 no.3
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    • pp.189-202
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    • 2016
  • This study aimed to investigate pre-service science teachers' perceptions of significance and usefulness of evolution and genetics. To this end, 82 pre-service biology teachers and 159 non-biology science teachers answered the items to measure the perceptions of significance and usefulness of evolution and genetics. The validity and reliability were examined using Cronbach alpha, two-dimensional rating scale model Rasch analysis, and factor analysis. The finding illustrated that the test items met the benchmark to be valid and reliable test items. Second, pre-service teachers' perception of significance and usefulness of evolution was independent to that of genetics. The level of pre-service teachers' perception of significance and usefulness of evolution was lower than the level of genetics. Lastly, the levels of pre-service teachers' perceptions of significance and usefulness of evolution and genetics were not significantly different across academic years and majors (biology and non-biology). The findings of this study stressed the importance of teaching significance and usefulness of evolution and genetics in pre-service science teacher education program.

A genetic approach to comprehend the complex and dynamic event of floral development: a review

  • Jatindra Nath Mohanty;Swayamprabha Sahoo;Puspanjali Mishra
    • Genomics & Informatics
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    • v.20 no.4
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    • pp.40.1-40.8
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    • 2022
  • The concepts of phylogeny and floral genetics play a crucial role in understanding the origin and diversification of flowers in angiosperms. Angiosperms evolved a great diversity of ways to display their flowers for reproductive success with variations in floral color, size, shape, scent, arrangements, and flowering time. The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences have driven new ecological adaptations, speciation, and angiosperm diversification. Evolutionary developmental biology seeks to uncover the developmental and genetic basis underlying morphological diversification. Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution. A number of regulatory genes controlling floral and inflorescence development have been identified in model plants such as Arabidopsis thaliana and Antirrhinum majus using forward genetics, and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics. Transcription factors are vital elements in systems that play crucial roles in linked gene expression in the evolution and development of flowers. Therefore, we review the sex-linked genes, mostly transcription factors, associated with the complex and dynamic event of floral development and briefly discuss the sex-linked genes that have been characterized through next-generation sequencing.

Role of Chromosome Changes in Crocodylus Evolution and Diversity

  • Srikulnath, Kornsorn;Thapana, Watcharaporn;Muangmai, Narongrit
    • Genomics & Informatics
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    • v.13 no.4
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    • pp.102-111
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    • 2015
  • The karyotypes of most species of crocodilians were studied using conventional and molecular cytogenetics. These provided an important contribution of chromosomal rearrangements for the evolutionary processes of Crocodylia and Sauropsida (birds and reptiles). The karyotypic features of crocodilians contain small diploid chromosome numbers (30~42), with little interspecific variation of the chromosome arm number (fundamental number) among crocodiles (56~60). This suggested that centric fusion and/or fission events occurred in the lineage, leading to crocodilian evolution and diversity. The chromosome numbers of Alligator, Caiman, Melanosuchus, Paleosuchus, Gavialis, Tomistoma, Mecistops, and Osteolaemus were stable within each genus, whereas those of Crocodylus (crocodylians) varied within the taxa. This agreed with molecular phylogeny that suggested a highly recent radiation of Crocodylus species. Karyotype analysis also suggests the direction of molecular phylogenetic placement among Crocodylus species and their migration from the Indo-Pacific to Africa and The New World. Crocodylus species originated from an ancestor in the Indo-Pacific around 9~16 million years ago (MYA) in the mid-Miocene, with a rapid radiation and dispersion into Africa 8~12 MYA. This was followed by a trans-Atlantic dispersion to the New World between 4~8 MYA in the Pliocene. The chromosomes provided a better understanding of crocodilian evolution and diversity, which will be useful for further study of the genome evolution in Crocodylia.

The Need for a New Curriculum in Clinical Genetic Education (임상유전학 교육에서 새로운 교과과정 개발의 필요성)

  • Lee, Chang-Woo
    • Korean Medical Education Review
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    • v.16 no.1
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    • pp.50-54
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    • 2014
  • It is becoming increasingly important for medical doctors to have a thorough understanding of human genetics and the ethical, legal, and social implications of genetic testing, counseling, and treatment. As genetic engineering and technology evolves, medical doctors will find themselves called in to counsel patients about a rapidly increasing number of diseases for which genetic testing and treatments are available. Medical doctors will need to master a new set of principles and clinical skills. A lack of knowledge about these issues and problems may lead to serious, lifelong or even fatal negative effects on patients. Medical genetics has moved from the study of rare conditions to the illumination of disorders that impact the entire spectrum of medical practice. This study demonstrates several areas in which medical genetics is clearly an important tool in medical practice and the necessity of establishing new curriculum for clinical genetic education in Korea. Medical students nearing graduation may lack genetic knowledge that is essential for daily practice because genetics has little or no place in clinical teaching. Medical schools should make extensive curriculum changes to increase students' awareness of clinical genetics and its ethical implications. The medical school curriculum will need creative new approaches to keeping up with the rapid pace of evolution of clinical genetics.

High School Students's Misconceptions on Genetics and Evolution (고등학생(高等學生)들의 유전(遺傳)과 진화(進化)에 대(對)한 오개념(誤槪念))

  • Chung, Wan-Ho;Cha, Hee-Young
    • Journal of The Korean Association For Science Education
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    • v.14 no.2
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    • pp.170-183
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    • 1994
  • In this study, in order to find our high school students' misconceptions on genetics and evolution, a free-answer form of questionnaire, specially designed through analysis of high school biology curriculum, was developed and sent to one hundred and eight high school students in Seoul area. Their responses were collected and qualitatively analyzed. Main results of the study can be summarized as follows: 1. Some students misunderstood that aquired chracters are inherited. 2. Several students weren't instructed clearly about gene. For example, they responsed that genes are not material, composed of proteins, exist only in reproductive cells and are not in plant cells at all. 3. Some students confused chromosome with chlorophyll, dorminant (in dorminant character) with excellent. They are caused by similar spells in Korean letter 4. Half students misconceptualized that organisms evolve just when their environment changes for the worse. 5. Many students believed orthogenesis.

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Study on Formative Assessment using Cartoon for 'Genetics and Evolution' Unit of Middle School (중학교 유전과 진화 단원의 만화를 활용한 형성평가에 대한 연구)

  • Lee, Kye-Young;So, Keum-Hyun;Yeau, Sung-Hee
    • Journal of The Korean Association For Science Education
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    • v.28 no.2
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    • pp.120-129
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    • 2008
  • In this study, 17 formative assessments using cartoon were developed for studying 'genetics and evolution' chapter in textbook of third grade of junior high school. And those were applied to 73 students in experimental group and 78 students in control group. We investigated if there was positive effect on students' perception, attitude about assessment and scholastic achievement. As a result, we could find the formative assessments using cartoon were effective to change students' negative perception and attitude to positive one. Especially, those were effective to make students to understand usefulness of assessment (p<.05), and to decrease a feeling of uneasiness about assessment (p<.01). Also, we could find the developed formative assessments using cartoon had more positive effect on raising scholastic achievement than formative assessment using descriptive passage (p<.05). It was considered that this was because the abstract concepts of 'genetics and evolution' chapter were described in pictures, so contexts of textbook and assessment questions became easier to understand. So, we could conclude that formative assessment using cartoon contributed to increase students' understanding of contexts of textbook and to increase their interests about study. And if this assessment method is applied to class actively, students' feeling of uneasiness about assessment can be easily overcome and it can also give them positive perception about assessment.

Genetic signature of strong recent positive selection at interleukin-32 gene in goat

  • Asif, Akhtar Rasool;Qadri, Sumayyah;Ijaz, Nabeel;Javed, Ruheena;Ansari, Abdur Rahman;Awais, Muhammd;Younus, Muhammad;Riaz, Hasan;Du, Xiaoyong
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.7
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    • pp.912-919
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    • 2017
  • Objective: Identification of the candidate genes that play key roles in phenotypic variations can provide new information about evolution and positive selection. Interleukin (IL)-32 is involved in many biological processes, however, its role for the immune response against various diseases in mammals is poorly understood. Therefore, the current investigation was performed for the better understanding of the molecular evolution and the positive selection of single nucleotide polymorphisms in IL-32 gene. Methods: By using fixation index ($F_{ST}$) based method, IL-32 (9375) gene was found to be outlier and under significant positive selection with the provisional combined allocation of mean heterozygosity and $F_{ST}$. Using nucleotide sequences of 11 mammalian species from National Center for Biotechnology Information database, the evolutionary selection of IL-32 gene was determined using Maximum likelihood model method, through four models (M1a, M2a, M7, and M8) in Codeml program of phylogenetic analysis by maximum liklihood. Results: IL-32 is detected under positive selection using the $F_{ST}$ simulations method. The phylogenetic tree revealed that goat IL-32 was in close resemblance with sheep IL-32. The coding nucleotide sequences were compared among 11 species and it was found that the goat IL-32 gene shared identity with sheep (96.54%), bison (91.97%), camel (58.39%), cat (56.59%), buffalo (56.50%), human (56.13%), dog (50.97%), horse (54.04%), and rabbit (53.41%) respectively. Conclusion: This study provides evidence for IL-32 gene as under significant positive selection in goat.

Expression of Vimentin Intermediate Filament for Vascular Development in Olive Flounder (Paralichthys olivaceus)

  • Yang, Hyun;Lee, Jang-Wook;Noh, Jae Koo;Kim, Hyun Chul;Park, Choul-Ji;Park, Jong-Won;Hwang, In Joon;Kim, Sung Yeon;Lee, Jeong-Ho
    • Development and Reproduction
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    • v.18 no.2
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    • pp.107-115
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    • 2014
  • Cardiovascular system is the primary organ to develop and reach a functional state, which underscores the essential role of the vasculature in the developing embryo. The vasculature is a highly specialized organ that functions in a number of key physiological works including the carrying of oxygen and nutrients to tissues. It is closely involved in the formation of heart, and hence it is essential for survival during the hatching period. The expression of genes involved during vascular development in the olive flounder (Paralichthys olivaceus) in the days after hatching is not fully understood. Therefore, we examined the expression patterns of genes activated during the development of flounder. Microscopic observations showed that formation of blood vessels is related to the expression of the vimentin gene. Also, the temporal expression patterns of this vimentin-like gene in the developmental stages and in the normal tissues of olive flounder. The purpose of this study was to examine the expression patterns of vimentin in normal tissues of the olive flounder and during the development of the vascular system in newly hatched olive flounders and HIF-1 plays a vital role in the formation of blood vessels during development. Vimentin expression was strong at the beginning of the development of blood vessels, and was present throughout all developmental stages. Our findings have important implications with respect to the roles of vimentin and HIF-1 in the development and evolution of the first blood vessels in olive flounder. Further studies are required to elucidate the vimentin-mediated hypoxic response signal transduction and to decipher the functional role of vimentin in developmental stages.