Login

|
|
3 point testModerator: BioTeam
5 posts • Page 1 of 1
3 point testHi, I have this data:
A three point testcross was made in corn. The alleles C and c result in colored versus colorless seeds, Wx and wx in nonwaxy versus waxy seeds, and Sh and sh in plump versus shrunken seeds. When plants grown from seeds heterozygous for each of these pairs of alleles were testcrossed, the progeny were as follows. colorless, nonwaxy, shrunken 84 colorless, nonwaxy, plump 974 colorless, waxy, shrunken 20 colorless, waxy, plump 2349 colored, waxy, shrunken 951 colored, waxy, plump 99 colored, nonwaxy, shrunken 2216 colored, nonwaxy, plump 15 and I need to find: a) the genotype of the heterozygous parent, b) the order of the three genes, c) the genetic distance between each gene and d) calculate interference I have done the problem, just wondering if I am right....... Genotype of heterozygous parent: cwxSh /CWxsh Gene order: C Sh Wx Distance: C-----→Sh = 29cM Sh---→Wx = 3.2cM Interference: 44% my other question is, what is the easiest way to find the gene order in a problem like this? I have been searching tests, etc and I can't find a good answer. They start to explain a visual method, but they just kinda stop and assume you know what they are talking about. I looked at the parental genotypes and the double recombinant genotypes and the order I came up with seems to work, but I am really not sure.........thanks all!
The easiest way to find the gene order is to look at the most numerous phenotypes which constitute your two parents. Now the least numerous is the double crosses(middle gene switched). So example:
Most: AB+C / A+BC+ Least: A+B+C / ABC+ Gene order BAC or CAB Living one day at a time;
Enjoying one moment at a time; Accepting hardships as the pathway to peace; ~Niebuhr
Well, I am still confused...not sure what exactly is switching. I know my parentals and double recombinants, and that lead me to the folowing gene order:
Parentals: cwxSh /CWxsh = Gene order: C Sh Wx double recombinants: CWxSh/cwxsh Also, when listing the gene order, do you list the dominants? Sorry, just feeling really lost and I am sure it is quite simple.....Are my answers correct? Thanks
5 posts • Page 1 of 1
Who is onlineUsers browsing this forum: No registered users and 0 guests |
© Biology-Online.org. All Rights Reserved. Register | Login | About Us | Contact Us | Link to Us | Disclaimer & Privacy
Science Network - Braintrack.com - University Directory | Chemicool.com - Chemistry | Logo design by LogoBee | Powered by phpBB