Sökning: "Sex ratio"
Visar resultat 1 - 5 av 215 avhandlingar innehållade orden Sex ratio.
Sammanfattning : Males and females differ in morphology and behaviour, so that selection acts differently on the two sexes. This changes the relative reproductive success of males and females, and it is beneficial for parents to bias the sex ratio of their broods in favour of the sex with the best survival and breeding prospects. LÄS MER
- Detta är en avhandling från Lund University, Faculty of Medicine
Sammanfattning : Pancreatic cancer represents three percent of all incident cancer cases in developed countries, but stands the 7th most common cause of cancer related death. Worldwide, pancreatic cancer is more common among men, however in Sweden, the incidence ratio between sexes is levelling. LÄS MER
3. Sex and symbionts New discoveries in local and regional patterns of coral ecology and reproductionDetta är en avhandling från Stockholm : Department of Systems Ecology, Stockholm University
Sammanfattning : Coral reefs belong to the most diverse and the most threatened ecosystems on earth. Anthropogenic stressors and climate change have led to mortalities at levels unprecedented in modern times. The aims of this thesis are to investigate aspects of the corals’ ability to reproduce, disperse, adapt and survive. LÄS MER
- Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis
Sammanfattning : Tree sparrows (Passer montanus) have been studied in two areas in Sweden since 1997. At both sites, tree sparrow eggs had remarkably low hatching success. On average only 60% of the eggs hatched. Analyses have shown that this was caused by embryonic mortality, which was highly sex biased. LÄS MER
5. Endocrine Disruption in Amphibians Developmental Effects of Ethynylestradiol and Clotrimazole on the Reproductive SystemDetta är en avhandling från Uppsala : Acta Universitatis Upsaliensis
Sammanfattning : Amphibian populations are declining world-wide and one of the suggested reasons is environmental pollutants. Studies of long-term effects on the reproductive system in frogs following larval exposure to environmental pollutants are scarce. It is therefore important to develop methods to study developmental reproductive toxicity in amphibians. LÄS MER