Studies of the fungus "Neurospora crassa" have contributed substantially to understanding how genes work. "N. crassa" is a type of red bread mold of the phylum "Ascomycota". It is used as a model organism because it is easy to grow and has a haploid life cycle that makes genetic analysis simple since recessive traits will show up in the offspring. Analysis of genetic recombination is facilitated by the ordered arrangement of the products of meiosis in ascospores. In its natural environment, "N. crassa" lives mainly in tropical and sub-tropical regions. It often can be found growing on dead plant matter after fires.