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Representation of Genetics in International Biology Olympiad
Šinknerová, Eliška ; Rothová, Olga (advisor) ; Matějková, Tereza (referee)
I chose this topic because biological competitions are an essential part of high school biology education. These competitions provide students with valuable opportunities to develop their skills in the field and can be highly motivating. The main goal of this thesis is to describe and analyse the representation of genetics and various genetic disciplines in the assignments of the last ten rounds of International Biology Olympiad (IBO) and to compare the representation of assignments from different disciplines in different countries. Another goal is to compare the frequency of genetic questions according to Bloom's taxonomy, the type of used representation and level of organization. This thesis focuses on the analysis of questions from genetics in IBO in the years 2009-2018. Genetics can be considered a discipline that binds most areas of biology, all its organizational levels, and it is a fundamental part of biology, thus being good field to examine this way. I divided the analysed questions into biological disciplines and questions belonging to genetics into the categories of Bloom's taxonomy (revised version), according to the representation used (diagram, graph, family tree, photo, table, taxonomic tree, map, electrophoresis result diagram, spectrometry result diagram, northern blot result...
"Golden' crops"- reason for their origin, construction, as well as use
Vlach, Jakub ; Rothová, Olga (advisor) ; Marková, Hana (referee)
Vitamin A deficiency is a long-term issue influencing mainly the population of poor countries. It causes a number of health problems (eyesight quality, susceptibility to infection diseases). Vitamin A is obtained naturally from food, however in poor countries there is a lack of varied diet rich in micronutrients. Local population is dependent on a few crop types actually planted and harvested is such regions. A sustainable way to improve this situation is growing of biofortified rice, maize, sweet potato, banana, sorghum, or cassava. These crops are called "golden crops" for their specific yellow to orange color. In the thesis, I thoroughly describe the biosynthesis of Provitamin A and the issue of its deficiency. Based on studied literature, I have compiled the currently known information about the production of golden rice and other golden crops consumed mainly in poor countries. There is a breeding method aiming at increasing the level of β-carotene in consumed parts of plants described for each particular crop type. Described methods are either conventional when the enriched plants are obtained through traditional breeding (sweet potato), or processes of genetic engineering are applied because of the insufficiency or impossibility to use conventional methods (banana, rice, cassava, sorghum)....
Genetic variability in growth, reproductive and photosynthetic parameters of plants and its changes by exogenously applied steroids
Rothová, Olga ; Holá, Dana (advisor) ; Motyka, Václav (referee) ; Hradilík, Jan (referee)
While animal steroid hormones are very well known and have been studied for a long time, in plants no steroid substances were known until relatively recently. Only in the second half of the past century brassinosteroids were discovered; later on, their hormonal function in plants was confirmed. Still a lot of unknown remains as regards their function in plant cells. This paper presents in its first part the evidence that brassinosteroids control in maize (Zea mays L.) grown under field conditions not only its morphology and yield but also some developmental/reproduction characteristics like e.g. number of female inflorescences or speed of the development of male inflorescences. Particular response of a plant depends, however, on the type of applied brassinosteroid, its concentration, and last but not least also on a particular maize genotype and developmental stage of the plant during applicatin. Impact of brassinosteroids on primary photosynthetic processes in plants has not been proven under these conditions, neither on the activity of photosystem (PS) I nor on the Hill reaction. No statistically significant differences in the content of photosynthetic pigments have been found either. Another topic dealt with in this thesis is the possible protective influence of brassinosteroids on plants...
Úloha brassinosteroidů v odpovědi různých genotypů kukuřice na změny v zásobování vodou.
Trubanová, Nina ; Rothová, Olga (advisor) ; Hnilička, František (referee)
Brassinosteroids (BRs) have been recognized to alleviate damages caused by drought stress and to enhance tolerance to water deficit. Soaking of maize kernels before the sowing in solution with different 24-epibrassinolide concentrations (especially the 10-8 M) had a positive effect on growth of plants before and after the stress period, although it did not affected relative water content and photosynthetic parameters. After the recovery under optimal conditions there were no differences among the treatments. When compared to spraying, soaking of maize kernels was not proved to have any advantages, though its positive effect on plants germination under water deficit conditions could be possible. Based on the results of the second season experiment it is not possible to deduce the role of exogenous BRs application (spraying with 24-epibrassinolide) or endogenous BRs biosynthesis (spraying with biosynthesis inhibitor - brassinazole) in maize plants subjected to water deficit. However, decrease in relative water content in contrast to chlorophylls content increase during the days following after drought stress onset in both cultivars (contrastive in drought sensitivity) challenges for further investigation of this problem. Understanding the role of BRs in plant drought tolerance and resistance is...
Polyploidy with specific view to paleopolyploidy and its detection
Kotz, Matěj ; Král, Jiří (advisor) ; Rothová, Olga (referee)
Polyploidy is a significant phenomenon in the evolution of eucaryotic organisms. It has been a subject of interest of biologists for decades and it has been studied particularly largely in plants, where it most often occurs. This thesis handles occurrence of poylploidy in organims and a special emphasis is laid on old polyploidization events occurrence of polyploidy in animal taxa. Furthermore, the types of polyploidy and obstacles are discussed here, that a polyploid organism has to tackle to stabilize its genome. That also includes the need to ensure the correct chromosome segregation in a meiotic division. A special case of polyploidy is paleopolyploidy (sometimes refered to as "ancient polyploidy" in English), which is an evolutionary old polyploidization event, that is followed by the process of diploidization. This process is characterized besides others by a large number of structural changes in chromosomes and a loss of some DNA sequences and a gradual transition of the polyploid genome to the cytologically diploid state. Because of these changes, it is difficult to detect a paleopolyploidy and the main part of this thesis is dedicated to this problem, in which the main approaches that might lead to its detection are discussed. Key words: polyploidy, animal, plant, meiosis, paleopolyploidy,...
Mutations in brassinosteroid biosynthetic genes and their effects on plant phenotype
Frimlová, Klára ; Rothová, Olga (advisor) ; Mašková, Petra (referee)
Brassinosteroids are important group of phytohormones, whose presence affects anatomy, morphology and development of plants. They occur in all vegetative and mainly generative organs. Brassinosteroids are biosynthesized via two main paths named early C-6 oxidation pathway and late C- 6 oxidation pathway. Brassinosteroid biosynthesis is catalyzed by enzymes from the group of cytochrome P450. Gene mutations - which affect brassinosteroid biosynthesis - have been studied especially in Arabidopsis thaliana L., Pisum sativum L., Solanum lycopersicum L. and Oryza sativa L. Mutations lead to changes in the composition and amount of brassinosteroids in plants. The reduced content of brassinosteroids is manifested by typical phenotype that includes reduced growth, reduced size of plant organs, and dark green leaves in mutant plants. The mutant phenotype can be reversed by exogenous application of brassinosteroids, which is nevertheless dependent on the concentration of the brassinosteroids used. Higher concentrations of brassinosteroids cause mostly inhibition of root elongation. Keywords: brassinosteroids, biosynthesis, mutant, phenotype
Role of brassinosteroids in plant response to drought stress
Trubanová, Nina ; Rothová, Olga (advisor) ; Urban, Milan (referee)
Brassinosteroids are steroid phytohormones with a wide range of effects. They improve survivance of plants exposed to drought stress, increase their resistence and yield therethrough. They regulate the response of plants directly (via synthesis of metabolits) and/or indirectly (via the induction of antioxidant compounds and enzymes), often in interaction with other phytohormones. Experiments studying influence of brassinosteroids on response of plants stressed with water deficit differ in several parameters. Their correct interpretation is complicated conseguently.

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