The case of fungi and fungus-like molds is a product of convergent evolution.

Myxomycota (plasmodial slime mold)
     These are brightly pigmented but do not perform photosynthesis.  In their feeding stage, they are a mass of amoeboids created from one zygote.  This mass is called a plasmodium because the amoeboids are not individual cells but one organism;  the structure of the plasmodium is coenzocytic:  there is a mass of cytoplasm with many, many, many synchronized diploid nuclei in one cell.  These molds actively consume food as they extend their pseudopodia for purposes of mobility.  When food is lacking, the coenzocyte creates a sporangium, or an elevated sac filled with potential haplotypes forms of the single plasmodium.  These haplotypes alternate between amoeboid and flagellated forms before they eventually fuse to create the diploid plasmodium in a process called syngamy.

Acrasiomycota (cellular slime mold)
     These are solitary cells when food is plentiful.  When food is scarce, these individual cells group together into a reproductive structure; however, there is no assimilation of the solitary cells:  all independent cells forming the reproductive unit are divided by their cell membranes.  As haploids, syngamy occurs during feeding to create a zygote that has a resistant coating around it.  The zygote then undergoes meiosis to reproduce the solitary cells.

Oomycota (water mold)
     These include water mold, white mold, and downy mold.  They consist of coenzocytic hyphae (fine branching filaments analogous to true fungi).  Diploidy is more prevalent unlike the other fungus-like molds.  Its sexual reproduction consists of egg nuclei in oogonium structures surrounded by sperm nuclei in structures named antheridial (like anther in flowers) hyphae.  Members of Oomycota also form flagellated zoospores and are decomposers in aquatic ecosystems.

Next:  "Algae."