kuzminpe

http://www.www.urch.com/forums/attachments/gre-biochemistry-cell-molecular-biology/7057-stereochemistry-oxaloacetate-citrate-tca-cycle-q94.png This question was taken from GRE Biochemistry subject mock exam. The answer index states that the correct answer is D carbons C4 and C6. However, there are no steric centers in the molecule, so there is no difference between C4 and C1. So couldn't the answer also be B with C1 and C4?

Hi, I have a bachelor in pharmaceutical chemistry but I am doing subject GRE in Biochemistry, molecular and cellular biology. The following question is from the mock exam. "In a series of two-factor crosses, 30 percent recombination occurs between gene A and gene B, and 26 percent recombination between gene B and gene C. If the order of genes on the chromosome is A-B-C, how much recombination will be seen between A and C in a two-factor cross? A 4% B 8% C 28% D 50% E 56% " I looked up the concept of recombination frequency and by my current understanding of this concept the answer should be E. However, the real answer is D. Please, someone explain how you get 50% distance between A and C. Thanks