Pedigrees - - as in biology? It's the diagram showing the phenotypes of a trait for a group of organisms... It's so frustrating and confusing. All I really need to know is what the difference between the genotypes of autosomal dominant and autosomal recessive are. I've looked all over the net...can't find nothing. I find the definitions of auto dom and auto rec, but I may as well be reading Swahili. I really have to get this for midterms. If anyone recalls high school bio or happens to be an expert on Punnett Squares and Pedigrees (genetics), PLEASE help me out. I would be so thankful.
You get one gene from each parent. Autosomal dominant - If one of the 2 genes has the trait then you inherit it. So one of two positive genes = the condition is expressed. Autosomal recessive - You need both genes to make the trait active. Therefore you can carry the gene, and not express the condition. With two genes you have a 50-50 chance of getting the gene from each parent. Two parents, 4 genes, 4 combinations, 25% chance of getting each of the four combinations.
25% chance of getting each of the four combinations, thats if each parent was heterozygous...meaning they carry one dominant gene and one recessive gene. ex: A gene= dominant B gene=recessive Mom has A and B gene so she is AB genotype. Dad has A and B gene so he is also AB genotype. MOM A B A AA -25% AB-25% DAD B AB-25% BB-25% You can see that since the A is dominant over the B...A will be expressed 75% of the time in the offspring(this is the phenotype...or physical manifestation of the genotype.) Feel free to test anymore of my excellent biology,genetics, health, or chemistry skills to your amusement! PS: I can't seem to get the punnett square to display correctly on the bbs, but if select reply with quotes than it will appear correctly.
Tsk, tsk... KR8...you might think of investing a few pesos in condoms next time you go to boystown... This site might help you out a little... site of the itches!!!!!!! you might want to scroll down to the picture and view the horror!!
