To make a linkage map in Drosophila, a three-point test cross was carried out. The parental cross was between homozygous
metabolic engineering and inheritance analysis shows exogenous gene introduction and pathway extension enable trait improvement. Consequently a c b emerges as the valid choice since it demonstrates metabolic extension and combinatorial biosynthesis, aligning with established principles in genetics and biotechnology literature.
Ref: Pierce, Genetics: A Conceptual Approach, 6th Edition, Chapter 3, discusses genotype-phenotype correlation and inheritance patterns providing framework for genetic transmission and metabolic engineering.
