The Monohybrid Cross Experiments of Dr. James Specht
The next round of experiments was designed to gain a more focused understanding of the genetic control of two of the mutant traits. Dr. Specht selected two mutants for these studies. One mutant grew normally at first and then began to develop lesions such that its leaves looked as if they had a pathogenic infection. This trait was called the disease lesion mutant.
The other mutant never grew normally but expressed an extreme dwarf phenotype. The plants are so small that it was surprising Dr. Specht even observed the original mutant plant in the field of M2s.
The disease lesion and dwarf M2 plants were both homozygous. What type of M3 rows did they produce? They generated rows of progeny that all expressed their unique phenotypes. Some of these M3 plants were then used in a monohybrid cross experiment.