Search for dissertations about: "ontogeni"

Found 5 swedish dissertations containing the word ontogeni.

2. 1. Ontogeny and Population Biology of a Sex-Limited Colour Polymorphism

   Author : Jessica Abbott; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; embryologi; ontogeni; animal morphology; embryology; Utvecklingsbiologi; Damselflies; Colour polymorphism; Development; Frequency-dependence; Morphology; growth animal ; ontogeny; Animal anatomy; Development biology; Djurs anatomi och morfologi; Population divergence; Animal ecology; Djurekologi;

   Abstract : This study has involved investigation of number of populations of the damselfly Ischnura elegans over several years, looking at frequency changes over time, morphological differences between the sexes and the morphs, differences in growth rate and development time, differences in fecundity between the morphs, and genetic differentiation between populations. I. READ MORE

4. 2. The balance between sex and asex: evolutionary genetic studies of reproductive variation in Allium vineale

   Author : Alf Ceplitis; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ontogeny; growth animal ; Allium vineale; Development biology; evolution; sexual reproduction; reproductive systems; embryology; Utvecklingsbiologi; ontogeni; embryologi; Genetics; cytogenetics; Genetik; cytogenetik;

   Abstract : Evolutionary theory predicts a disadvantage to sexual reproduction. This manifests itself either by the higher growth rate of asexual females in a dioecious species, or by the higher transmission rate of a gene conferring asexual female function to its carriers in a hermaphrodite species. READ MORE

5. 3. The role of polysaccharide modifications during Drosophila development

   Author : Florian Lüders; Institutionen för experimentell medicinsk vetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ontogeni; growth animal ; embryologi; Development biology; Decapentaplegic; Hedgehog; Wingless; Sulfation; Pipe; Glycosaminoglycan; Glycosyltransferase; ontogeny; embryology; Utvecklingsbiologi;

   Abstract : Glucosides attached to proteins and lipids have been shown to modulate the activity of signal transduction pathways regulating growth and patterning processes during animal development. In particular, O-linked glycans such as glycosaminoglycans (GAGs) have been implicated in modulation of growth factor signaling pathways. READ MORE

6. 4. Trilobites from the Middle and Upper Ordovician Andersön Shale Formation in Jämtland and the equivalent Killeröd Formation in Skåne, Sweden

   Author : Kristina Månsson; Berggrundsgeologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; fysisk geografi; Geologi; physical geography; Geology; Sweden; Jämtland; Skåne; Upper Ordovician; Middle Ordovician; Killeröd Formation; Andersön Shale Formation; ontogeny; biostratigraphy; Trilobita; taxonomy; trilobite associations; Systematic zoology; zoogeography; Zoologisk systematik; djurgeografi; Development biology; growth animal ; embryology; Utvecklingsbiologi; ontogeni; embryologi;

   Abstract : Trilobites from the Middle and Upper Ordovician Andersön Shale Formation in Jämtland, central Sweden, and the Middle Ordovician Killeröd Formation in Skåne (Scania), southern Sweden, are revised and discussed. These formations have several genera and a few species in common, e.g. READ MORE

7. 5. The palaeolimnological record of regime shifts in lakes in response to climate change

   Author : Linda Randsalu Wendrup; Kvartärgeologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; palaeolimnology; regime shifts; thresholds; alternative stable states; climate change; ecosystem dynamics; diatoms; hydrocarbons; monitoring; lake sediments; shallow lakes; 8.2 ka event;

   Abstract : Regime shifts in lake ecosystems can occur in response to both abrupt and continuous climate change, and the imprints they leave in palaeolimnological records allow us to investigate and better understand patterns and processes governing ecological changes on geological time scales. This thesis aims at investigating palaeolimnological records of regime shifts in lakes during the Holocene to explore how lake ecosystems responded to climate changes and anthropogenic activities and to identify thresholds or tipping points that produced regime shifts. READ MORE