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In the off-spring of crosses between Drosophila simulans and its island derivative Drosophila mauritiana, female hybrids are fertile but male hybrids are sterile. Recent studies have shown that a critical gene for gender determination in Drosophila known as the sex-lethal gene is highly misregulated in D. melanogaster and D. simulans hybrids ...
However, when hybrids are produced between both species, the gene flow between the two will continue to be impeded as the hybrid males are sterile. Also, and in contrast with the great vigor shown by the sterile males, the descendants of the backcrosses of the hybrid females with the parent species are weak and notoriously non-viable.
Hybrid sterility can be caused by different closely related species breeding and producing offspring. These animals are usually sterile due to the different numbers of chromosomes between the two parents. The imbalance results in offspring that is viable but not fertile, as is the case with the mule.
A mule is a sterile hybrid of a male donkey and a female horse.Mules are smaller than horses but stronger than donkeys, making them useful as pack animals.. In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction.
In humans, barring intersex conditions causing aneuploidy and other unusual states, it is the male that is heterogametic, with XY sex chromosomes.. Haldane's rule is an observation about the early stage of speciation, formulated in 1922 by the British evolutionary biologist J. B. S. Haldane, that states that if — in a species hybrid — only one sex is inviable or sterile, that sex is more ...
Delivering both hybrid and plug-in hybrid models, the top-of-the-line plug-in hybrid NX450h+ has a spirited 302 hp and 0-60 in just 5.6 seconds. The interior offers plenty of headroom and rear ...
The Quadrantid meteor shower is one of the strongest, and quickest, meteor showers of the year. Here’s what you need to know to observe it during peak activity.
Ethylene oxide treatment is the most common chemical sterilization method, used for approximately 70% of total sterilizations, and for over 50% of all disposable medical devices. [ 26 ] [ 27 ] Ethylene oxide treatment is generally carried out between 30 and 60 °C (86 and 140 °F) with relative humidity above 30% and a gas concentration between ...