Heterozygous hybrids are produced by crossing a red cow with a white bull which is called polygenic inheritance. Thanks!
Horse coat colors
Philosophy of biology
Horses exhibit a diverse array of coat colors and distinctive markings. A specialized vocabulary has evolved to describe them.
While most horses remain the same color throughout life, a few, over the course of several years, will develop a different coat color from that with which they were born. Most white markings are present at birth, and the underlying skin color of a horse does not change, absent disease.
The philosophy of biology is a subfield of philosophy of science, which deals with epistemological, metaphysical, and ethical issues in the biological and biomedical sciences. Although philosophers of science and philosophers generally have long been interested in biology (e.g., Aristotle, Descartes, and even Kant), philosophy of biology only emerged as an independent field of philosophy in the 1960s and 1970s. Philosophers of science then began paying increasing attention to biology, from the rise of Neodarwinism in the 1930s and 1940s to the discovery of the structure of DNA in 1953 to more recent advances in genetic engineering. Other key ideas include the reduction of all life processes to biochemical reactions, and the incorporation of psychology into a broader neuroscience.
Quantitative trait locus
Classical genetics consists of the technique and methodologies of genetics that predate the advent of molecular biology. A key discovery of classical genetics in eukaryotes was genetic linkage. The observation that some genes do not segregate independently at meiosis broke the laws of Mendelian inheritance, and provided science with a way to map characteristics to a location on the chromosomes. Linkage maps are still used today, especially in breeding for plant improvement.
After the discovery of the genetic code and such tools of cloning as restriction enzymes, the avenues of investigation open to geneticists were greatly broadened. Some classical genetic ideas have been supplanted with the mechanistic understanding brought by molecular discoveries, but many remain intact and in use. Classical genetics is often contrasted with reverse genetics, and aspects of molecular biology are sometimes referred to as molecular genetics.
Quantitative trait loci (QTLs) are stretches of DNA containing or linked to the genes that underlie a quantitative trait. Mapping regions of the genome that contain genes involved in specifying a quantitative trait is done using molecular tags such as AFLP or, more commonly SNPs. This is an early step in identifying and sequencing the actual genes underlying trait variation. Quantitative traits refer to phenotypes (characteristics) that vary in degree and can be attributed to polygenic effects, i.e., product of two or more genes, and their environment.
Blue Grey is a type of beef cattle popular in Scotland and the north of England.
It is traditionally produced by crossing a whitebred shorthorn bull with black Galloway cows. The offspring gain beefiness from their sire and hardiness from their upland dams, and their colour is a blue roan which is regarded as attractive by many farmers.