Arabidopsis plants that only reach half their normal height have a mutation in the biosynthesis of the plant growth factor gibberellin.
However, long stalks in a grain field present a danger
Different neural circuits process environmental signals depending on the state of satiation.
low quantities of carbon dioxide to be a sign of danger
External stimuli control the hormonal regulation of our eating behaviour.
The danger that the exposure to such images will result
Some animals produce more offspring than others do. Hormones like prolactin and corticosterone can exercise a crucial influence on the behaviour of birds in the breeding season and therefore on their reproductive success. Scientists from the Max Planck Institute for Ornithology in Radolfzell and their colleagues at the universities of Princeton and Edinburgh have now demonstrated that hormone levels not only play a key role during the breeding season, but already dictate, long in advance, how many eggs a breeding pair will lay, when they will lay them and how often. An animal’s hormonal constitution is thus of major significance for its reproductive success, and is possibly an important driving force of evolution. (Proceedings of the Royal Society B, January 19, 2011)
When the bird is exposed to sudden danger and significant
The Herschel Space Observatory catches a glimpse of the minor planet during its rendezvous with Earth
The minor planet does not pose a danger for Earth,
Equality of opportunities: facts & figures
time, the implementation of new categories bears the danger
Leaf beetles fascinate us because of their amazing variety of shapes and rich colouring. Their larvae, however, are dangerous plant pests. Larvae of the leaf beetle Chrysomela lapponica attack two different tree species: willow and birch. To fend off predator attacks, the beetle larvae produce toxic butyric acid esters or salicylaldehyde, whose precursors they ingest with their leafy food. Scientists of the Max Planck Institute for Chemical Ecology in Jena, Germany, now found that a fundamental change in the genome has emerged in beetles that have specialized in birch: The activity of the salicylaldehyde producing enzyme salicyl alcohol oxidase (SAO) is missing in these populations, whereas it is present in willow feeders. For birch beetles, the loss of this enzyme and thereby the loss of salicylaldehyde is advantageous: the enzyme is no longer needed because its substrate salicyl alcohol is only present in willow leaves, but not in birch. Birch beetles can therefore save resources instead of costly producing the enzyme. First and foremost, however, the loss of salicylaldehyde also means that birch feeding populations do not betray themselves to their own enemies anymore, who can trace them because of the odorous substance.
function externally and metabolically: In case of danger
Leaf beetles fascinate us because of their amazing variety of shapes and rich colouring. Their larvae, however, are dangerous plant pests. Larvae of the leaf beetle Chrysomela lapponica attack two different tree species: willow and birch. To fend off predator attacks, the beetle larvae produce toxic butyric acid esters or salicylaldehyde, whose precursors they ingest with their leafy food. Scientists of the Max Planck Institute for Chemical Ecology in Jena, Germany, now found that a fundamental change in the genome has emerged in beetles that have specialized in birch: The activity of the salicylaldehyde producing enzyme salicyl alcohol oxidase (SAO) is missing in these populations, whereas it is present in willow feeders. For birch beetles, the loss of this enzyme and thereby the loss of salicylaldehyde is advantageous: the enzyme is no longer needed because its substrate salicyl alcohol is only present in willow leaves, but not in birch. Birch beetles can therefore save resources instead of costly producing the enzyme. First and foremost, however, the loss of salicylaldehyde also means that birch feeding populations do not betray themselves to their own enemies anymore, who can trace them because of the odorous substance.
function externally and metabolically: In case of danger
Neurobiologists can now activate specific nerve cells to study the association between sensations and negative experiences
flies to learn to associate a potential source of danger
Female chimpanzees’ reproductive success decreases in times of strong territorial conflict with other groups
new index of neighbor pressure that reflects the danger
