You are doing lab work with a new species of beetle. You have
isolated lines that breed true for either blue shells and long
antenna or green shells and short antenna. Crossing these lines
yields F1 progeny with blue shells and long antenna. Crossing F1
progeny with beetles that have green shells and short antenna
yields the following progeny:
Blue shell, long
antenna
67
Green shell, short
antenna 53
Blue shell, short
antenna
30
Green shell, long
antenna
25
Assuming that the genes are linked, what is the map distance
between them in m.u.? Round your answer to the nearest whole
number.