In pea plants, with the genes for flower color, purple flowers (P) are dominant over red (p). With the genes?

for pollen grain shape, long pollen grains (L) are dominant over round (l). Plants heterozygous for purple flowersand long pollen grains (PpLl) are test-crossed with the homozygous recessive (ppll). The following offspring are produced:


purple, long 118


red, round 122


purple, round 32


red, long 28





Are the genes for flower color and pollen grain shape on the same chromosome? Can you figure out how far apart they are on the chromosome?

FlowersBirthday FlowersSympathy FlowersThey are linked on the same chromosome.





purple, long 118 = parental


red, round 122 = parental


purple, round 32 = recombinants


red, long 28 = recombinants





Total = 500


Total recombinants = 32+28 = 60.


% recombinants = 60/500 = 12%.


Cross over frequency = 12% = 12 centimorgan (abbreviated cM) or map unit (m.u.)





12 map units apart.visual arts