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Origin, degeneration and detection of sex chromosomes
Jílková, Klára ; Král, Jiří (advisor) ; Kratochvíl, Lukáš (referee)
Sex chromosomes evolved from a pair of autosomes and they are differentiated as a result of supression of recombination. This process leads to a successive degradation of odd sex chromosome (alosome), which is becoming genetically inert finally or even excluded. Fundamental processes taking part in degeneration of alosome are Muller's ratchet, genetic hitchhiking, background selection, accumulation of transposable elements and constitutive heterochromatin. Indeed, these processes take part in either degeneration of both Y or W chromosomes. Remarkably, these alosomes show different rates of degeneration, most probably due to 1) different structure of male and female gonads as well as 2) different course of gametogenesis in both sexes. Furthermore, rate of alosome degeneration is usually lower in plants because they are haploid during the major part of life cycle. Other mechanisms of sex chromosome evolution involve rearrangements between autosomes and gonosomes, nondisjunctions and fissions of original sex chromosomes, transformation of B chromosomes into sex chromosomes or non-random segregation of autosomes with sex chromosomes. Other phenomenon that appears in sex chromosome evolution is transition between XY/XX and ZW/ZZ systems or transition between chromosomal sex determination and epigamy. Actually,...
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Garden in Children's Literature - its presentation, role and symbolism in The Secret Garden and Tom's Midnight Garden
Jílková, Klára ; Chalupský, Petr (advisor) ; Farrell, Mark Robert (referee)
In my diploma thesis, I deal with the topic of the garden as it is presented in Frances Hodgson Burnett's The Secret Garden and Ann Philippa Pearce's Tom's Midnight Garden. In the beginning, I discuss the reasons for the attractivity of this topic among children's authors in general, and introduce Burnett and Pearce. In the following chapters I focus mainly on the role of the gardens in the characters' lives, showing the positive effect they have on the characters, helping them to gradually change for the better. I concern myself with several themes, including the way and the circumstances in which the two gardens are discovered, the setting of the stories, and the magical aspects of both gardens. I also deal with the differences in the perception of time and with the interconnectivity of time levels in the stories. At the end of this thesis there is a chapter devoted to the way both authors present their gardens and on the means they use for their descriptions.
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Evaluation of the success of mission EUBAM and EUFOR
Jílková, Klára ; Weiss, Tomáš (advisor) ; Šír, Jan (referee)
Bachelor thesis deals with evaluation of EU missions, namely EUBAM Moldova-Ukraine and EUFOR Althea. A comparison of two case studies was chosen as a method of work research. The work first deals with the evaluation of each mission and compares the advantages and disadvantages of civilian missions and military operations. These two case studies have been chosen because the countries in which the missions operate, are geographically close, as well as they are neighboring countries of the European Union, which could become potential Member States in the future. Missions are evaluated on the basis of predefined criteria, which were selected on the basis of an analysis of the literature according to the scales compiled by the author. An integral part of the work is a brief introduction to EU Common Foreign and Security Policy, followed by case studies and their evaluation. The last chapter of the thesis is a comparison of the advantages and disadvantages of the EUBAM Moldova-Ukraine civilian mission and the EUFOR Althea military operation. The bachelor thesis concludes that the strengths and weaknesses of civilian missions and military operations are in many cases quite different.
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Evolution of selected karyotype characters in tetrapulmonate arachnids
Jílková, Klára ; Král, Jiří (advisor) ; Marec, František (referee)
The class Arachnida is not thoroughly explored from the cytogenetic point of view. Previous studies suggest a high diversity of karyotypes and sex determination in arachnids. This study deals with the evolution of sex chomosomes, nucleolar organizer regions (NOR), and telomeric repeats in the tetrapulmonate clade of arachnids, particularly in groups of ancient origin. Sex chromosomes were detected in two orders. Detection of NORs in a large set of species supports the hypothesis that the ancestral karyotype of arachnids contained NOR on one pair of autosomes only. The number of NORs has increased during the evolution of some groups of Pedipalpi. The NORs are located in terminal or subterminal chromosomal regions in most tetrapulmonates. The occurrence of the "insect" telomeric motif was confirmed in majority of tetrapulmonates. Interstitital telomeric repeats were not detected with the exception of one species. Keywords: arachnids, meiosis, sex chromosomes, telomeres, nucleolar organizer, heterochromatin
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Origin, degeneration and detection of sex chromosomes
Jílková, Klára ; Král, Jiří (advisor) ; Kratochvíl, Lukáš (referee)
Sex chromosomes evolved from a pair of autosomes and they are differentiated as a result of supression of recombination. This process leads to a successive degradation of odd sex chromosome (alosome), which is becoming genetically inert finally or even excluded. Fundamental processes taking part in degeneration of alosome are Muller's ratchet, genetic hitchhiking, background selection, accumulation of transposable elements and constitutive heterochromatin. Indeed, these processes take part in either degeneration of both Y or W chromosomes. Remarkably, these alosomes show different rates of degeneration, most probably due to 1) different structure of male and female gonads as well as 2) different course of gametogenesis in both sexes. Furthermore, rate of alosome degeneration is usually lower in plants because they are haploid during the major part of life cycle. Other mechanisms of sex chromosome evolution involve rearrangements between autosomes and gonosomes, nondisjunctions and fissions of original sex chromosomes, transformation of B chromosomes into sex chromosomes or non-random segregation of autosomes with sex chromosomes. Other phenomenon that appears in sex chromosome evolution is transition between XY/XX and ZW/ZZ systems or transition between chromosomal sex determination and epigamy. Actually,...
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Garden in Children's Literature - its presentation, role and symbolism in The Secret Garden and Tom's Midnight Garden
Jílková, Klára ; Chalupský, Petr (advisor) ; Farrell, Mark Robert (referee)
In my diploma thesis, I deal with the topic of the garden as it is presented in Frances Hodgson Burnett's The Secret Garden and Ann Philippa Pearce's Tom's Midnight Garden. In the beginning, I discuss the reasons for the attractivity of this topic among children's authors in general, and introduce Burnett and Pearce. In the following chapters I focus mainly on the role of the gardens in the characters' lives, showing the positive effect they have on the characters, helping them to gradually change for the better. I concern myself with several themes, including the way and the circumstances in which the two gardens are discovered, the setting of the stories, and the magical aspects of both gardens. I also deal with the differences in the perception of time and with the interconnectivity of time levels in the stories. At the end of this thesis there is a chapter devoted to the way both authors present their gardens and on the means they use for their descriptions.
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