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Population differentiation of Ochrophytes
Mensová, Anna ; Jurdíková, Katarína (advisor) ; Kulichová, Jana (referee)
This bachelor thesis deals with a differentiation of populations of Ochrophytes (photosynthetic Stramenopiles). Natural populations can differ in many aspects and their differentiation is observed on several levels. Ecophysiological and morphological differences are very often caused by phenotypic plasticity, which is a flexible answer to changing conditions of habitats. Genetic differentiation could express an adaptation to the local environmental conditions. The adaptation and a long-term isolation of populations are considered to be the leading factors in genetic differentiation. The other factors contributing to genetic differentiation are random evolutionary events such as founder effect or genetic drift. Detailed studies of populations lead to uncover the factors that cause the differentiation of populations as well as they contribute to the understanding of speciation mechanisms. The thesis compiled the information about different types of variability among populations within the classes of Ochrophytes.
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Sexual reproduction of ochrophyte algae
Procházková, Kateřina ; Eliáš, Marek (advisor) ; Kulichová, Jana (referee)
Sexual reproduction is one of the specific features of eukaryotes. Almost all the knowledge that we have about the sexual process is based on studies conducted on animals and plants. In fact, we know only a tiny fraction of what protist organisms could reveal about distribution and other aspects of the sexual process. For the vast majority of them we miss any evidence that the sexual process actually occurs. However, it is conceivable that the putative protist asexuality is only a human artifact. Likewise, for most ochrophyte algae, which are the main subject of this thesis, the sexual process is unknown. It has been observed only in individuals belonging to six of the sixteen hitherto described classes of Ochrophyta. In some cases, an enviromnental factor that stimulates the formation of gametes was also found. The gradual clarification of the phylogeny that we can expect in the years coming, along with knowledge of biology of ochrophyte algae, can provide more information about sexuality in this group.
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Population differentiation of Ochrophytes
Mensová, Anna ; Jurdíková, Katarína (advisor) ; Kulichová, Jana (referee)
This bachelor thesis deals with a differentiation of populations of Ochrophytes (photosynthetic Stramenopiles). Natural populations can differ in many aspects and their differentiation is observed on several levels. Ecophysiological and morphological differences are very often caused by phenotypic plasticity, which is a flexible answer to changing conditions of habitats. Genetic differentiation could express an adaptation to the local environmental conditions. The adaptation and a long-term isolation of populations are considered to be the leading factors in genetic differentiation. The other factors contributing to genetic differentiation are random evolutionary events such as founder effect or genetic drift. Detailed studies of populations lead to uncover the factors that cause the differentiation of populations as well as they contribute to the understanding of speciation mechanisms. The thesis compiled the information about different types of variability among populations within the classes of Ochrophytes.
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|
|
Sexual reproduction of ochrophyte algae
Procházková, Kateřina ; Eliáš, Marek (advisor) ; Kulichová, Jana (referee)
Sexual reproduction is one of the specific features of eukaryotes. Almost all the knowledge that we have about the sexual process is based on studies conducted on animals and plants. In fact, we know only a tiny fraction of what protist organisms could reveal about distribution and other aspects of the sexual process. For the vast majority of them we miss any evidence that the sexual process actually occurs. However, it is conceivable that the putative protist asexuality is only a human artifact. Likewise, for most ochrophyte algae, which are the main subject of this thesis, the sexual process is unknown. It has been observed only in individuals belonging to six of the sixteen hitherto described classes of Ochrophyta. In some cases, an enviromnental factor that stimulates the formation of gametes was also found. The gradual clarification of the phylogeny that we can expect in the years coming, along with knowledge of biology of ochrophyte algae, can provide more information about sexuality in this group.
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