haploid
Most fungi are multicellular, but some exist as single cells. Fungi spend most of their life cycle in the haploid state. They form diploid cells only during sexual reproduction. Like the cells of protists and plants, the cells of fungi have cell walls. But fungi are unique in having cell walls made of chitin instead of cellulose. Chitin is a tough carbohydrate that also makes up the exoskeleton outer skeleton of insects and related organisms.