Genetic 7,673 Views
Basic Genetic Concepts
Most of you are undoubtedly aware that color and certain diseases such as progressive retinal atrophy (PRA) are inherited — that is, passed down from one or both the parents. However, you may wonder how a trait that does not appear in the dam's pedigree can suddenly turn up in a litter out of Ch. Jake Hugelsberg. Is it inherited or just an accident? Surely, Jake has been used so often that someone would have noticed if the problem came from him. Just how much of a role does genetics play in health, general conformation and temperament? Probably you would like to know exactly what traits are inherited; but, once someone starts talking about "partial dominance" or "expressivity," you get glassy-eyed. The objective of this guide is to explain some of the basics of inheritance and how to use these concepts to breed healthier dogs — hopefully without losing you in complex technical jargon.
Many people label any problem that appears to be inherited a "genetic disease." However, though there are legitimate genetic diseases, there are also a variety of problems that have an inherited component, but are of a fundamentally different nature. Dealing effectively with any genetic problem requires an understanding of the relationship between the genes (genotype) and the phenotype. In many cases this is lacking. In this article, I would like to describe some of the differences in order to give breeders and owners a better understanding of what they are dealing with. 
On this page is a set of "typical" genetics questions that are best answered using a punnett square. It would be handy for you to have a pencil & some paper to work out the problems, & then you can click to see an explained solution to each. For those who would benefit from a step-by-step explaination of how to use a p-square, see "Baby Steps through the Punnet Square".
