American chestnut trees were once the predominant species of…

American chestnut trees were once the predominant species of tree in the eastern half of North America but this species has become virtually extinct due to a disease – chestnut blight.  Some of the last surviving trees were crossed to European chestnut trees which are resistant to the disease.  While European chestnut trees can provide potential genes for resistance to the disease, they also have lower nutritional quality of the chestnuts.  You hypothesize that the disease resistance and poor nutritional quality are both dominant traits.  The F1 trees from a cross of the European and American chestnut trees are self-pollinated and you observe the following off-spring.  Develop a hypothesis and calculate a chi-square value. Disease resistant, poor nutritional quality – 139 trees Disease resistant, high nutritional quality – 45 trees Disease sensitive, poor nutritional quality – 54 trees Disease sensitive, high nutritional quality – 18 trees

A geneticist has estimated the number of exchanges that occu…

A geneticist has estimated the number of exchanges that occurred during meiosis on each of the 100 chromatids that were recovered in gametes. The data are as follows: Number of chiasmata Number of cells observed 0 18 1 20 2 30 3 16 4 16 What is the genetic length in cM of the chromosome analyzed in this study?