Assume that investigators crossed a strain of flies carrying the dominant eye mu
ID: 57656 • Letter: A
Question
Assume that investigators crossed a strain of flies carrying the dominant eye mutation Lobe on the second chromosome with a strain homozygous for the second chromosome recessive mutations smooth abdomen and straw body. The F1 Lobe females were then backcrossed with homozygous smooth abdomen, straw body males and the following phenotypes were observed: smooth abdomen, straw body 820 Lobe 780 smooth abdomen, Lobe 42 straw body 58 smooth abdomen 148 Lobe, straw body 152 (a) Give the gene order and map units between these three loci - draw the map!. (b) What is the coefficient of coincidence? (c) what is the interference?
Explanation / Answer
a. The map units and gene order is given as follows:
Smooth abdomen--------- 5------Lobe------15-------Straw body
This means that lobe will be in middle.
b.The coefficient of coincidence will be 0.
c. Interference is given as:
1- coefficient of coincidence
now putting the value of coefficient of coincidence we get
1-0 = 1 or we can say interference 100%.
This indicates that there won't be any double crossovers.