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Time course imaging of two maize inbreds and their F1 hybrid (middle) exhibiting heterosis.. Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a hybrid offspring.
The three traits of pivotal temperature (the temperature at which the sex ratio is 50%), maternal nest-site choice, and nesting phenology have been identified as the key traits of TSD that can change, and of these, only the pivotal temperature is significantly heritable, this would have to increase by 27 standard deviations to compensate for a ...
All alligators determine the sex of their offspring by the temperature of the nest. Many other sex-determination systems exist. In some species of reptiles, including alligators, some turtles, and the tuatara, sex is determined by the temperature at which the egg is incubated during a temperature-sensitive period. There are no examples of ...
In these species, one or more genes are present on their Y chromosome that determine maleness. In this process, an X chromosome and a Y chromosome act to determine the sex of offspring, often due to genes located on the Y chromosome that code for maleness. Offspring have two sex chromosomes: an offspring with two X chromosomes (XX) will develop ...
The sex of alligators is determined by nest temperature. The sex of most amniote vertebrates, such as mammals and birds, is determined genetically. [12] However, some reptiles have temperature-dependent sex determination, where sex is permanently determined by thermal conditions experienced during the middle third of embryonic development.
The word hybridity was in use in English since the early 17th century and gained popular currency in the 19th century. Charles Darwin used the term in 1837 in reference to his experiments in cross-fertilization in plants. The concept of hybridity has been fraught with negative connotations from its incipience.
Nyctinastic movements are associated with diurnal light and temperature changes and controlled by the circadian clock. It has been argued that for plants that display foliar nyctinasty, it is a crucial mechanism for survival; however, most plants do not exhibit any nyctinastic movements. [1]
The Kirkendall effect is the motion of the interface between two metals that occurs due to the difference in diffusion rates of the metal atoms. The effect can be observed, for example, by placing insoluble markers at the interface between a pure metal and an alloy containing that metal, and heating to a temperature where atomic diffusion is reasonable for the given timescale; the boundary ...