Tetrad Analysis


Link to raw image collection for Sordaria

This was an exercise of haploid genetics. The gene that imparts black coloration to the spores of the fungus, Sordaria, is the allele to the one that imparts a tan color. Since the spores are haploid the presence of either allele is always expressed in the phenotype. The area of this plate that is black has the genotype for black color, the area that is tan has the genotype for tan. We are interested in viewing fruiting bodies along the boundary of the two strains where we will find asci resulting from the meiosis of a heterozygous zygote. These asci are interstrain asci.


  • Link to view of all possible ascus phenotypes
  • Link to view of fruiting bodies
  • Link to view of intra-strain fruiting bodies
  • Link to view of interstrain fruiting body
  • Link to view of an ascus
  • Link to a view of interstrain asci not derived from crossing over
  • Link to view of interstrain fruiting bodies derived from crossing over