Confused on 2 questions here If a recombination frequency between two genes is 1.5%, what is the distance between the genes in map units on the linkage map? a. Impossible to determine, because the interference is not known. b. 1.5 c. 3 d. 0.75 Recombination frequencies a. arise from completely random genetic exchange. b. are the same for all genes. c. decrease with distance. d. are the same for cis and trans heterozygotes. I thought it was b for the first part a for the second part and but I'm wrong. Can someone explain?
Sorry forgot to add my explanation b. Each % frequency of recombination equals one map unit between the genes. So 1.5% recombination frequency = 1.5 map units apart will result in 1.5% recombination a. It can't be (b), because genes are all distances apart; it can't be (c), because frequencies increase with increasing distance; it can't be (d), because the distance between genes is the same whether the alleles are cis or trans loci. So I thought it was a.
I thought I was right but when I entered it into the system I was wrong. I'm sure the first part is right and I thought the second part was right but I guess not.
I would probably agree too. It is a strange way of examining to ask which of four statements is correct. It seems to me though I am a bit rusty, that you have to a little bit psych what some of the questions mean, if it's any consolation.
I don't think it's C. I did think it may be D is the recombination frequency was being dtermined by phenotype. But, this seems less likely when I came across the following: http://books.google.co.uk/books?id=...e&q=recombination frequency cis trans&f=false (Page 114)
I was thinking D and C. D because as the loci become further apart (low recombination values) the probability of a second crossover increases and the recombination value is overestimated. The only value less than 1.5 is 0.75 (D). I don't know what is meant by "interference" in answer A but that could be correct as well. Edit. you are right C can't be correct
I finally found some material that helped. I got it right and the answer was D. Thanks guys for your help I really appreciate it.
I've been talking about question 2. For which one is the answer D? What did you arrive at for number 2? The link I recommended explicitly states that trans and cis heterozygotes exhibit equal recombination frequencies.