Previous genetic linkage crosses have determined that recombination frequencies are 6% for genes A and B, 4% for genes B and C,
10% for genes C and D, and 11% for genes D and E. The sum of these frequencies between genes A and E is 31%. Why does the recombination distance between these genes as determined by adding the intervals between adjacent linked genes differ from the distance determined by the test cross?
Because as distance between genes increase, the probability of one recombination grows, but the probability of two recombinations occuring also increases
Explanation:
If we only score the outcome as yes or no to recombination between two genes, then one recombination is a yes, but two is a no and three is a yes again (and so on).
The purpose of fermentation in yeast is the same as that in muscle and bacteria, to replenish the supply of NAD+ for glycolysis, but this process occurs in two steps: Alcoholic fermentation consists of pyruvate being first converted into acetaldehyde by the enzyme pyruvate decarboxylase and releasing CO2.