In maize, the dominant allele Hs (hairy sheath) results in hairy leaf sheaths at all stages of development, whereas the dominant allele Tp-1 (teopod-1) results in many small, partially podded ears with a reduced number of kernels. Mutant plants are crossed to produce the double heterozygous genotype Hs tp-1/hs Tp-1 (hs and tp-1 are the wild-type alleles, which are recessive), and a testcross is carried out. Among 800 progeny were 432 plants that had either hairy leaf sheaths or teopod ears, and 368 plants with either both of these traits or neither. Required:
a. Is there significant evidence of linkage between these genes as judged by a chi-square test?
b. What is the estimated frequency of recombination?