Bean plants may have different symptoms when infected with a virus. Some show local lesions that do not seriously harm the plant; others show general systemic infection. The following genetic analysis was made:
P: local lesions x systemic infection
F1: all local lesions
F2: 785 local lesions : 269 systemic infection

What is the likely genetic basis of this difference in beans? Evaluate your hypothesis using a chi-square test. Assign gene symbols to the genotypes occurring in the genetic analysis. Design a testcross to verify your assumptions.