In the garden pea, orange pods (orp) are recessive to green pods (Orp), and sensitivity to pea mosaic virus (mo) is recessive to resistance to the virus (Mo). A plant with orange pods and sensitivity to the virus was crossed to a true-breeding plant with green pods and resistance to the virus. The F1 plants were then testcrossed to plants with orange pods and sensitivity to the virus.

The following results were obtained for the F2 offspring:

160 orange pods, virus-sensitive 165 green pods, virus-resistant 36 orange pods, virus-resistant 39 green pods, virus-sensitive 400 total 

A. Conduct a chi square test to see if these two genes are linked.

B. If they are linked, calculate the map distance between the two genes.