A cross is made between a heterozygote, +++/abc, and a recessive homozygote, abc/abc. Analysis of the progeny gave the following results: + + 450 + + C 10 a + c 70 + b c 210 + b a + + + 65 200 a b c 460 a b + 15 What is the map distance between the a and b genes? 34.45 map units 36.23 map units 38.51 map units 40.20 map units 43.01 map units