Talk about monobiontic haplontic sexual reproduction of algae

Spirogyra is a filamentous haploid green alga (gametophyte) which is common in freshwater habitats. When sexual reproduction begins, the individual cells of adjacent aligned filaments (of two different mating types) form protuberances which grow and fuse to form a conjugation tube connecting the opposite pair of cells. Fertilization occurs when the condensed protoplast of cells of one filament, migrates through a conjugation tube and fuses with the protoplast of the adjacent cells of the second mating filament, forming a zygote. Each filament of protoplast moving cells is considered as a male filament, while the stationary one functions as a female filament. Sexual reproduction is done by conjugation. The resulting zygote forms a zygospore with a tough resistant outer covering within the cells of the female filament. The zygospores break away from the parent when the filament cell walls rupture. After a period of dormancy, on return of favorable conditions, these zygotes undergo meiosis and germinate, resulting in new haploid filaments of Spirogyra