Diploid cells undergo meiosis to produce haploid spores. Most Foraminifera undergo a heteromorphic alternation of generations between haploid gamont and diploid agamont forms. Within the mushroom diploid cells are formed, later dividing into haploid spores. However, asexual species can be either haploid or diploid. These undergo meiosis to form haploid spores. They have life cycles with alternating haploid and diploid phases. The zygote undergoes meiosis immediately, creating four haploid cells. Most fungi reproduce sexually, having both a haploid and diploid stage in their life cycles. Houseflies have a small number of chromosomes, haploid 6 or diploid 12. The sporophyte produces free-swimming haploid spores by meiosis that germinate into haploid gametophytes. The life cycle of coccolithophores is characterized by an alternation of diploid and haploid phases. Most fungi have both a haploid and a diploid stage in their life cycles. The haploid spores germinate and grow into a haploid gametophyte. However, since plants have an alternation of diploid and haploid generations some differences exist. Coccolithophorids are predominantly found as single, free-floating haploid or diploid cells.