Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 48

In the experiment of Figure 6.7, the researchers followed the inheritance pattern of chromosomes that were abnormal at both ends to correlate genetic recombination with the physical exchange of chromosome pieces. Is it necessary to use a chromosome that is abnormal at both ends, or could the researchers have used a parental strain with two abnormal versions of chromosome 9, one with a knob at one end and its homolog with a translocation at the other end
FIGURE 6.7 Experimental correlation between genetic recombination and crossing over.
Starting materials: Two different strains of corn. One strain (referred to as parent A) had an abnormal chromosome 9 (knobbed/ translocation) with a dominant C allele and a recessive wx allele. It also had a cytologically normal copy of chromosome 9 that carried the recessive c allele and the dominant Wx allele. Its genotype was Cc Wxwx. The other strain (referred to as parent B) had two normal versions of chromosome 9. The genotype of this strain was cc Wxwx.