Soybean, Glycine max L., and elodea, Elodea canadensis Michx, leaves were exposed to sublethal and lethal temperatures and examined by light microscopy. Loss of chlorophyll and swollen chloroplasts were observed in cells of elodea leaves exposed to sublethal temperatures. At the thermal death point of leaf cells of elodea and soybean, there was a disorganization of the tonoplast membrane, plasm...

Animal physiology, ecology and evolution are affected by temperature and it is expected that community structure will be strongly influenced by global warming. This is particularly relevant in the tropics, where organisms are already living close to their upper temperature limits and hence are highly vulnerable to rising temperature. Here we present data on upper temperature limits of 34 tropic...

toxic effects of malathion and endosulfan to fertile chicken eggs were determined. in-jection of 1.25, 2.5, 5.0 and 10.0 mg/egg of malathion into yolk sac of fertile eggs prior to incubation caused mortality of 10.0, 30.0, 83.33 and 93.33% respectively. similar trend was observed with injection of endosulfan doses. malathion and endosulfan at 1.25 mg/egg caused no pronounced ld50 increase in mo...

The extent to which phenotypic plasticity might mediate short-term responses to environmental change is controversial. Nonetheless, theoretical work has made the prediction that plasticity should be common, especially in predictably variable environments by comparison with those that are either stable or unpredictable. Here we examine these predictions by comparing the phenotypic plasticity of ...

Embryos of Xenopus laevis reared in media with various low (less than or equal to 10(-5) M) magnesium ion concentrations will exhibit differing degrees of a potentially lethal magnesium starvation syndrome depending on the ion concentration and rearing temperature. The higher the rearing temperature or the lower the magnesium ion content of the medium the more severely the syndrome will be expr...

Laboratory trials were carried out on the influence of low temperatures on adult survival, reproduction and egg hatch of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera Bostrichidae). Temperatures of 3, 7, 12, 17 and 27 °C were studied. Results show the lethal time (LT) required for killing 5%, 50% and 95% of the tested insects was significantly affected by temperature but not adu...

Attempts to link physiological thermal tolerance global species distributions have relied on lethal temperature limits, yet many organisms lose fertility at sublethal temperatures. Here we show that, across 43 Drosophila species, better match male-sterilizing temperatures than This suggests that may be determined by limits reproduction, not survival, meaning underestimating the impacts of clima...