Concept explainers
An organism of the genotype AaBbCc was testcrossed to a triply recessive organism (aabbcc). The genotypes of the progeny are in the following table.
AaBbCc | 20 | AaBbcc | 20 |
aabbCc | 20 | aabbcc | 20 |
AabbCc | 5 | Aabbcc | 5 |
aaBbCc | 5 | aaBbcc | 5 |
(a) Assuming simple dominance and recessiveness in each gene pair, if these three genes were all assorting independently, how many genotypic and
(b) Answer part (a) again, assuming the three genes are so tightly linked on a single chromosome that no crossover gametes were recovered in the sample of offspring.
(c) What can you conclude from the actual data about the location of the three genes in relation to one another?
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