Mendelian Genetics
Much of our understanding of genetics comes from the study of Mendelian traits, which is traits that illustrate the laws of inheritance. These laws were first brought up in the 1860s by Gregor Mendel, ¨the father of genetics.¨ Mendel had his own ideas on genetics and inheritance, he even spent years researching this by crossing pea plants.
Mendel believed that for any given trait, a person inherits one gene from each parent, therefore they have two genes. We know that the opposite forms of these units are called alleles. If the two alleles that form an identical trait, then the individual is homozygous (BB) and if the two genes are different, it is heterozygous (Bb). Medel also "made up" the words dominant and recessive. |
Here is an sample problem for Mendelian Genetics :
In cats, long hair is recessive to short hair. A true-breeding (homozygous) short-haired male is mated to a long-haired female. What will their kittens look like? From this problem, we know that long hair is recessive, h. That means short hair is dominant, H. It also says homozygous, which means the same, so it is HH and hh. After finding out the information, we have to put it into a punnett square. After solving the punnett square, we need to make ratios of what the kittens could possibly look like. The genotype is the possible genes, in this case, Hh, HH, or hh. The phenotype is the possible traits, in this case, short-haired or long-haired kittens. Telling from the ratios, there is a 100% chance of the kittens to be short-haired. Therefore, the kittens will have short hair.
|