This lack of cross walls may be the secret behind the evolutionary success of this widespread group of organisms. Fungi can move materials like nutrients and proteins back and forth very quickly by cytoplasmic streaming . Fungal digestion is extracellular, with the hyphae secreting powerful enzymes to digest the host tissue, then absorbing the breakdown products through their cell walls. Organisms that feed in such a fashion are called saprobes. We use many of the same terms for fungal reproduction that we use to describe analogous structures in plants.
Spores develop in a sporangium .
A hyphal tips that develop into a sexual reproductive structure is called a gametangium . The nuclei inside the fungal hyphae are haploid, unlike the diploid cells of most plants and animals. Therefore, fungi don't have to undergo meiosis before fertilization. Fungi reproduce by conjugation , a fusion of nuclei analogous to conjugation in bacteria and certain types of algae. These projections, called gametangia , meet and fuse together.