Search results
Results from the WOW.Com Content Network
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 ...
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.
Working in the early 20th century T.H. Morgan, was the first to use Drosophila to explore heredity. Primarily on the basis of work with D. melanogaster, Morgan and his colleagues C.B. Bridges, A.H. Sturtevant, and H.J. Mueller developed a chromosome theory of heredity, for which Morgan was awarded a Nobel Prize in 1933.
The sterility of many interspecific hybrids in angiosperms has been widely recognised and studied. [33] Interspecific sterility of hybrids in plants has multiple possible causes. These may be genetic, related to the genomes, or the interaction between nuclear and cytoplasmic factors, as will be discussed in the corresponding section.
Chausie, a hybrid between a jungle cat and domestic cat. Subfamily Pantherinae. Genus Panthera. Ligers and tigons (crosses between a lion and a tiger) and other Panthera hybrids such as the lijagulep. Species P. tigris. A hybrid between a Bengal tiger and a Siberian tiger is an example of an intra-specific hybrid. Family Canidae
The P element is a class II transposon, and moves by a DNA-based "cut and paste" mechanism. The recognition sequence comprises four exons separated by three introns . [ 3 ] Complete splicing of the introns produces the transposase enzyme, while alternative partial splicing of introns 1 and 2, leaving only intron 3 in the mRNA transcript ...
A bear that rampaged through a Japanese supermarket for two days was lured out with food coated in honey, local officials said. The animal was trapped and later killed on Monday, police said.
Hybrid incompatibility occurs when the offspring of two closely related species are not viable or suffer from infertility. Charles Darwin posited that hybrid incompatibility is not a product of natural selection, stating that the phenomenon is an outcome of the hybridizing species diverging, rather than something that is directly acted upon by selective pressures. [4]