The alleles such as ad, pro, paba, and bi show recessive phenotype. They depict adenine, proline, para-aminobenzoic acid, and biotin, respectively. The growth medium must have all the above nutrients for the survival of the mutant strains. The parental strains require the above growth supplements. However, the heterokaryon does not require them, since it consists of all the four genes capable of synthesizing them. The recessive w and y alleles control the color of the asexual spores, thereby giving rise to the colony color. The “wstrain shows green coloration. The “wy” strain shows white coloration. The “wy” strain shows yellow coloration. The “wy” strain shows white coloration. The heterokaryon of the first and the second strains is not green. The heterokaryon shows a mixture of yellow and white spores. It has a mottled appearance. Diploidization is a relatively rare case. The two haploid nuclei fuse together. They produce a diploid nucleus in such cases. Hence, the spores in these diploid cells would also be diploid. These cells do not require growth supplements since they show genotype with wild-type alleles. Mostly, they give rise to green colonies on a growth medium or a solid medium.