Title: What's the purpose of a Monohybrid, Dihybrid, reciporcial cross and simple test cross? Post by: khaos_ on Oct 9, 2016 Hey guys, I'm studying for my genetics exam and I've run into a few issues. My question is, What's the purpose of a Monohybrid, Dihybrid, reciporcial cross and simple test cross? The focus for these questions can from a drosophila lab I did.
For Monohybrid, I know that you cross 2 true breeding parents, and this tells you whether an allele is dom or recessive and also if it's x linked or autosomal, however, what exact tells you if it's x linked or not? Also, for a recessive leth For dihybrid, I know you cross two heterozygous genes and this tell you about whether the genes are linked or not. If the Principle of Indepedant assort. is correct then you get 4 gamates with a 1:1:1:1 ratio, correct? For reciprocial, I know it's backcrossing. So you cross an individual from the f1 generation with it's parent, or another individual with the same genotype as the parent. I read that it helps determine if the gene is sex linked or autosomal, but what exactly does that look like? Lastly, a simple test cross. I googled this and looked in my book but I literally can't find anything about it, or any examples. Thanks for the help, all examples are welcomed (I do better when I can see it and take time to make sense of it!) Title: Re: What's the purpose of a Monohybrid, Dihybrid, reciporcial cross and simple test cross? Post by: psyche360 on Oct 9, 2016 Monohybrid crosses are used to determine one trait of an offspring.
Dihybrid crosses are used to determine two traits of an offspring at the same time. Reciprocal crosses are used to determine the mode (sex-linked or autosomal) of inheritance. The trait in question in the first cross is associated with the female and in the second cross with the male. If the results of both crosses are the same, autosomal inheritance is indicate. If the results are different, sex-linked inheritance is indicated. A testcross is used to determine if the genotype of a plant with the dominant phenotype is homozygous or heterozygous. |