National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
KT/HAK/KUP High-affinity Transporters in Plants
Šustr, Marek ; Tylová, Edita (advisor) ; Vaňková, Radomíra (referee) ; Gloser, Vít (referee)
Due to its essential role in plant metabolism and often low availability in the soil, sufficient potassium uptake and management are among the challenges plants face to survive in different environments. Since all potassium functions are related to the transport of the monovalent cation K+ , research focuses on the transporters responsible for K+ uptake and allocation. In addition to playing an essential role in potassium nutrition, K+ transporters also mediate the uptake of pollutants such as Cs. Radioisotopes 134 Cs and 137 Cs released from nuclear bomb tests and nuclear power plant accidents remain in the environment and their accumulation in plants is being studied to reveal the risks of crop production in contaminated soils as well as the possibility of remediating contaminated soil through plants. Ion transport also seems to be a major driver of plant adaptation to unfavourable environments. Several ion transporters appear to be involved in the adaptation of Arabidopsis arenosa populations to serpentine soils, including the potassium transporter AaKUP9. This thesis summarises my effort to characterise two transporters from KT/HAK/KUP family, AtKUP7 and AtKUP9, in Arabidopsis thaliana, and related projects. For AtKUP9, I have significantly expanded the knowledge of its involvement in...
Histology of fish gills - processing and evaluation of preparations
KOCOUR, Jakub
Histology is the science that deals with the microscopic structure and structure of the tissues of organisms. This science is unique in that it deals with the study of tissues cut into very thin sections. This allows us to look into microscopic structures that may not be visible to the naked eye. The aim of this work was to develop a literature review where the main task was to describe the structure of the gills, the critical points in their histological processing and to classify the gill changes. The aim was also to create a photographic documentation of the histological preparation process. The first part of this thesis is devoted to fish gills. The gills are a multifunctional organ that is constantly in contact with the surrounding water. It is a medium for the exchange of gases and other substances and is very sensitive to external stimuli. Through the gills of fish, various ions and substances are exchanged, taken in and excreted. An interesting feature is, for example, the passage of nitrite ions, which enter the body of the fish through the Cl-/HCO3- exchanger. Such passage is prevented by chloride ions, which are competitively excreted with nitrite ions. In the next part of this thesis are the topic of methods of histological processing of fish. Several histological processing options are described in this thesis, which lead to the same goal, i.e. a histological, mostly also permanent preparation. During preparation, one step is staining. The most common dye is haematoxylin-eosin. This dye shows the cellular structures very well. However, some structures are more difficult to distinguish from each other, in which case special staining methods can be used. All these properties of gills make it an organ that is suitable for many fish health evaluation. Despite this, the gills, specifically the histological evaluation of the gills, are usually only an additional evaluation.
Phaeocystis - a key organism in dimethylsulfoniopropionate production; ecological and physiological functions of DMSP
Füllsacková, Alena ; Němcová, Yvonne (advisor) ; Pusztai, Martin (referee)
Dimethylsulfoniopropionate (DMSP) is an organic sulfur compound with an important ecological and physiological functions. DMSP is a major precursor for dimethylsulfid (DMS). DMSP is produced by variety of halophytic plants and phytoplankton for the purposes of osmotic regulation, antioxidation and protection from predators. It is especially widespread among the marine phytoplankton and it is ubiquitous in the euphotic zone. DMS and DMSP are also involved in flux of carbon and sulfur. Marine emissions of DMS have a particularly important role as precursors of atmospheric sulfur-containing aerosols that influence the Earth's climate system through direct backscatter of solar radiation and through cloud formation. DMSP is produced mainly by phytoplankton, because this group of organism is very large, I'll focus on Phaeocystis. Phaeocystis is a genus of marine phytoplankton with a worldwide distribution. It has a polymorphic life cycle alternating free-living cells and colonies but develops massive blooms under the colony form. Among the 10 species, only 3 (P. pouchetii, P. antarctica, P. globosa) have been reported as blooming species. DMSP is produced intracellulary and it is released as DMS. DMS concentration is high during the growth of the cells, predation or senescence. The production of DMSP is...
Utilization of Biology Olympiad in schools and implementation of selected tasks into highschool teaching.
Dvořáková, Darina ; Janštová, Vanda (advisor) ; Drda Morávková, Alena (referee)
This thesis deals with the Biology Olympiad and remaking of selected tasks of region round. The remaked tasks can be used in highschool education. The thesis includes theoretical and practical part. The theoretical part provides general information about the Biology Olympiad (BiO), charts the achievements of Czech students in International Biology Olympiad (IBO), includes literary review of selected topics. The practical part encompass four remaked tasks of different topics: Eucaryotic cell as a mosaic, Water in life of animals, Animals' areas and their distribution, History of the flora in Czech Republic. The tasks are processed in the form of worksheets. The worksheets were tested at schools. Knowledge of students was tested by using of created pretests and posttests. The practical part also presents the result of research based on a questionnaire survey focused on the involvement of school in BiO and teachers' opinions on these topics.
Physiology and functional anatomy of nectarivorous birds
Sejfová, Zuzana ; Janeček, Štěpán (advisor) ; Sam, Kateřina (referee)
Hummingbirds, sunbirds and a large part of honeyeaters belong to the most specialized nectarivores. During the evolution they have developed a number of adaptations in reaction to the specificity of their diet. The amount of studies focused on the adaptations connected with the digestion of nectar is not big, but is still growing. One of the characteristics of these birds is very fast and effective transport of consumed sugars across the intestinal epithelium. Furthermore they are tolerant to a very low nitrogen intake and extremely high daily intake of water. Sunbirds and honeyeaters are able to modulate the rate of water absorption in the intestine, but hummingbirds are not and they absorb almost all the consumed water. During the evolution excessive water intake together with a low concentration of salt presented in the diet led to changes in renal morphology that allows the production of an exceptionally dilute urine. The hovering flight of hummingbirds is well known and very well studied. The unique anatomy of hummingbird's wings allows the power production also during upstroke. Thanks to this hummingbirds are able to hover for a very long time and even in condition that are unsuitable for flight. Also sunbirds and honeyeaters sometimes hover during feeding. Nevertheless the mechanics of their hovering...
Adaptation mechanisms to wide salinity gradient in algae; transitions between marine and freshwater environments in chrysophytes
Knotek, Petr ; Němcová, Yvonne (advisor) ; Pusztai, Martin (referee)
The transition from the marine to the freshwater environment and vice versa is a key event in the evolution of organisms. Although these transitions are relatively rare from an evolutionary point of view, most large groups of organisms have undergone this event at least once. The marine and freshwater environment differs in many aspects, especially salinity. During the transition between these two environments, the organisms are forced to overcome a significant salinity gradient and adapt to changes in the osmotic potential. However, biotic factors also play an important role, especially competition and predation in the new environment. The aim of the bachelor 's thesis is to provide comprehensive information on the mechanisms of adaptation to a wide gradient of salinity in algae in general and to focus on freshwater-marine transitions in chrysophytes, that occurred repeatedly and relatively frequently in the course of evolution. Key words: chrysophytes, Chrysophyceae, salinity gradient, osmoregulation, marine- freshwater transition
Potassium in plant osmoregulation
Kholová, Kateřina ; Tylová, Edita (advisor) ; Konrádová, Hana (referee)
Potassium is very mobile in plants and is transported across membranes using transporters and channels. It is present in the ionic form K+ in plants. Also, in the form of this ion, K+ is taken up by plants from the soil solution. The uptake is mediated by the transporter HAK5 and by the channel AKT1. The transfer of K+ to the xylem is provided by the channel SKOR and the transporter KUP7. The role of potassium as an osmotically active element is crucial. K+ helps to regulate the amount of water in the cells and thus to maintain the turgor. Turgor is important for maintaining the shape of the plant cells and for its growth. Stomatal guard cells are used as a model system for describing processes related to the K+ osmotic function. Movement of K+ is involved in the regulation of opening and closing of stomata on the principle of turgor changes. Transport of K+ into guard cells is provided by channels KAT1, KAT2, AKT1 and AKT2. On the contrary, K+ release is mediated by the channel GORK on the plasma membrane and TPK1 on the tonoplast. K+ supports also the transport of assimilates in the phloem, where the channel AKT2 plays a role. The osmotic functions of K+ are the main topic of this bachelor thesis, which summarizes current knowledge about transport mechanisms necessary for the function of K+ as osmotically...
Phaeocystis - a key organism in dimethylsulfoniopropionate production; ecological and physiological functions of DMSP
Füllsacková, Alena ; Němcová, Yvonne (advisor) ; Pusztai, Martin (referee)
Dimethylsulfoniopropionate (DMSP) is an organic sulfur compound with an important ecological and physiological functions. DMSP is a major precursor for dimethylsulfid (DMS). DMSP is produced by variety of halophytic plants and phytoplankton for the purposes of osmotic regulation, antioxidation and protection from predators. It is especially widespread among the marine phytoplankton and it is ubiquitous in the euphotic zone. DMS and DMSP are also involved in flux of carbon and sulfur. Marine emissions of DMS have a particularly important role as precursors of atmospheric sulfur-containing aerosols that influence the Earth's climate system through direct backscatter of solar radiation and through cloud formation. DMSP is produced mainly by phytoplankton, because this group of organism is very large, I'll focus on Phaeocystis. Phaeocystis is a genus of marine phytoplankton with a worldwide distribution. It has a polymorphic life cycle alternating free-living cells and colonies but develops massive blooms under the colony form. Among the 10 species, only 3 (P. pouchetii, P. antarctica, P. globosa) have been reported as blooming species. DMSP is produced intracellulary and it is released as DMS. DMS concentration is high during the growth of the cells, predation or senescence. The production of DMSP is...
Physiology and functional anatomy of nectarivorous birds
Sejfová, Zuzana ; Janeček, Štěpán (advisor) ; Sam, Kateřina (referee)
Hummingbirds, sunbirds and a large part of honeyeaters belong to the most specialized nectarivores. During the evolution they have developed a number of adaptations in reaction to the specificity of their diet. The amount of studies focused on the adaptations connected with the digestion of nectar is not big, but is still growing. One of the characteristics of these birds is very fast and effective transport of consumed sugars across the intestinal epithelium. Furthermore they are tolerant to a very low nitrogen intake and extremely high daily intake of water. Sunbirds and honeyeaters are able to modulate the rate of water absorption in the intestine, but hummingbirds are not and they absorb almost all the consumed water. During the evolution excessive water intake together with a low concentration of salt presented in the diet led to changes in renal morphology that allows the production of an exceptionally dilute urine. The hovering flight of hummingbirds is well known and very well studied. The unique anatomy of hummingbird's wings allows the power production also during upstroke. Thanks to this hummingbirds are able to hover for a very long time and even in condition that are unsuitable for flight. Also sunbirds and honeyeaters sometimes hover during feeding. Nevertheless the mechanics of their hovering...
Utilization of Biology Olympiad in schools and implementation of selected tasks into highschool teaching.
Dvořáková, Darina ; Janštová, Vanda (advisor) ; Drda Morávková, Alena (referee)
This thesis deals with the Biology Olympiad and remaking of selected tasks of region round. The remaked tasks can be used in highschool education. The thesis includes theoretical and practical part. The theoretical part provides general information about the Biology Olympiad (BiO), charts the achievements of Czech students in International Biology Olympiad (IBO), includes literary review of selected topics. The practical part encompass four remaked tasks of different topics: Eucaryotic cell as a mosaic, Water in life of animals, Animals' areas and their distribution, History of the flora in Czech Republic. The tasks are processed in the form of worksheets. The worksheets were tested at schools. Knowledge of students was tested by using of created pretests and posttests. The practical part also presents the result of research based on a questionnaire survey focused on the involvement of school in BiO and teachers' opinions on these topics.

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