Ascospores are spores contained or produced in the ascus. This spore is unique to the fungi classified as Ascomycota. Ascospores are formed in the asci under optimal conditions. Generally, a single ascospore will contain eight ascospores. Eight spores are produced by meiosis and mitosis. Two meioses change the nucleus of the original diploid zygote into four haploids. In other words, a single primitive diploid cell at the beginning of the whole process contains two complete sets of chromosomes. To prepare for meiosis, all DNA in the two groups are copied, for a total of four groups. The nucleus of the four groups divides twice and is divided into four new nuclei, each of which has a complete set of chromosomes. After this process, each of the four new cell nuclei copies its DNA and divides through mitosis. As a result, the ascus will contain four pairs of spores. Then the ascospores are released from the ascus.