• 제목/요약/키워드: Biology I

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Four Freshwater Eutardigades from Korea with Description of Isohypsibius brevitubulatus n. SP.

  • Rho, Hyun-Soo;Moon, Seung-Yeo;Chang, Cheon-Young;Kim, Won
    • Animal cells and systems
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    • 제1권2호
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    • pp.271-279
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    • 1997
  • As a result of examining the specimens collected from various freshwater bodies since 1995, four eutardigrades are added to Korean fauna: lsohypsibius brevitubulatus n. sp., I. baldii (Ramazzotti), I. marcellinoi (Binda and Pilato), and Diphascon (Diphascon) higginsi Binda. I. brevitubulatus n. sp. differs from its congeners by having a combination of the following characteristics: smooth cuticle, rather big body size, short and broad buccal tube, presence of lunules, and pharynx bearing 3 rod-like macroplacoids without microplacoid. All the species are illustrated and briefly commented on their habitats with the associated fauna.

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Restriction pattern of the nucleic acid of Synechococcus sp. cyanophage

  • Park, Jong-Geun;Kim, Min;Choi, Yong-Keel;Yoon, Sung-Nyo
    • Journal of Microbiology
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    • 제34권1호
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    • pp.1-6
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    • 1996
  • The nucleic acid of Synechococcus sp. cyanophage was identified as double-stranded DNA by the result of digestion with enzymes such as exonucleases, DNase, and S1 nuclease, and by acridine orange staining. The cyanophage DNA was cleaved with several restriciton ehdonucleases such as ApaI, BamHI, Bg/II, HaeIII, Eco RI, HindIII, PstI, AND aPAI gave the clearest sets of bands on agarose gels and the fragment numbers for each were 12, 20, 29, 20, and 7, respectively. The sums of the size from Bam HI and PstI digestions were estimated approximately 227$\pm$4 kb, which are in agreement with the result of the pulsed field gel electrphoresis. This virus is thought to have the largest genosome among those of known cyanophages, which corresponds to the largest haed ot 90 nm when compared with the head sizes of cyanophages discovered since 1963.

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An Analysis of the Concepts that Should be Taught to Achieve Class Objectives of Genetics Unit in Biology

  • Lim, Soo-Min;Kim, Jeong-A;Sonn, Jong-Kyung;Jeong, Jae-Hoon;Kim, Young-Shin;Song, Ha-Young
    • 한국과학교육학회지
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    • 제29권7호
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    • pp.767-782
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    • 2009
  • The researchers who are studying biology and teachers who are teaching biology think that the genetics-related concepts are highly significant than other concepts in biology. With such background, researches on the identification of major concepts have been under way to guide in biology class. Minimal research has been carried out, however, on what concepts should be taught to achieve the specific objectives of the class in relation to the unit of genetics in middle and high school. Accordingly this study was designed to determine the concepts of genetics that should be taught to achieve the objectives of the genetics unit in secondary school. For this purpose 5 instructional objectives of the genetics unit on the 9th grade and 4 instructional objectives of Biology I were selected and the concepts that were taught to achieve class objectives. The survey was conducted among 114 science teachers from middle schools and 85 biology teachers from high schools. The results indicated that 9.1 and 10.2 concepts on average were taught in the 9th grade and in Biology I respectively. Moreover statistical difference in the number of concepts that were taught according to the teachers' teaching experiences appeared among the middle school teachers (p<.05). But such statistical difference did not appear among the high school teachers (p>.05). Furthermore the concepts for the 9th grade consist of the basic genetics concepts although Biology I concepts were integrated and advanced contents for same concepts. Thus this finding suggests that concepts of genetics units to be taught in middle and high school were in linkage.

Identification of Critical Residues for Plasminogen Binding by the αX I-domain of the β2 integrin, αXβ2

  • Gang, Jongyun;Choi, Jeongsuk;Lee, Joo Hee;Nham, Sang-Uk
    • Molecules and Cells
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    • 제24권2호
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    • pp.240-246
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    • 2007
  • The ${\beta}2$ integrins on leukocytes play important roles in cell adhesion, migration and phagocytosis. One of the ${\beta}2$ integrins, ${\alpha}X{\beta}2$ (CD11c/CD18), is known to bind ligands such as fibrinogen, Thy-1 and iC3b, but its function is not well characterized. To understand its biological roles, we attempted to identify novel ligands. The functional moiety of ${\alpha}X{\beta}2$, the ${\alpha}X$ I-domain, was found to bind plasminogen, the zymogen of plasmin, with moderate affinity ($1.92{\times}10^{-6}M$) in the presence of $Mg^{2+}$ or $Mn^{2+}$. The ${\beta}D-{\alpha}5$ loop of the ${\alpha}X$ I-domain proved to be responsible for binding, and lysine residues ($Lys^{242}$, $Lys^{243}$) in the loop were the most important for recognizing plasminogen. An excess amount of the lysine analog, 6-aminohexanoic acid, inhibited ${\alpha}X$ I-domain binding to plasminogen, indicating that binding is lysine-dependent. The results of this study indicate that leukocytes regulate plasminogen activation, and consequently plasmin activities, through an interaction with ${\alpha}X{\beta}2$ integrin.

Genetic Engineering for Detection of Endocrine Disruption using I-18 C Gene Expression in Chironomus riparius

  • Kwak Inn-Sil
    • 환경생물
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    • 제23권3호
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    • pp.269-274
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    • 2005
  • The 2D/E gel analysis for polypeptide expression reflecting I-18 C gene (early-ecdysterone inducible gene) has conducted the emerged C. riparius adults from larval phase exposure to tebufenozide acting as an ecdysteroidal molting hormone. Control group, the amount of ORE II of the I-18 C gene was larger than that of ORE I of this gene. After treatments, ORE I of the I-18 C gene was overexpressed as the polypeptide, whereas ORF II of this gene was expressed as the polypeptide and was clearly reduced expression. Accordingly, we consider that tebufenozide exhibited endocrine disruptions related processing of ecdysteroid receptor protein reflecting ORF II of I-18 C gene. Also, earlier emergence day was related overexpressed polypeptide reflecting ORE I of I-18 C gene. In this study result, tebufenozide induced changing of physiological condition, and then polypeptide expression reflecting early-ecdysterone inducible I-18 C gene was different between control group and exposure group.