Scalariform conjugation:
Occurs between the two filament and seen in heterothallic/dioeious species
1. Two filament of opposite strands come closer and lie parallel to each other throughout their length and get surrounded by commom Mucilagenous sheath(Due to attraction)
2. The opposite cells of two filaments produce small papillae outgrowth /Processes from their opposir e walls.
3. These papillate outgrowth increase in their size and join through their anterior end. By this time filament secretes enzyme cytase. Two filament secrete the enzyme cytase due to the activity of which the partition wall is sissolved between the two process forming a continuing passage conjugation tube. The ladder like structure is formed due to conjugation of many cells. Same time the protoplast get contracted forms gametes known as Gametangia. Thus, forms gametes are Isogametes in gametangia(bag to hold gamete) out of the isogametes one gamete shows motility and can be determined as male gamete. The male gametes enters through conjugation and enters the female gametangia and fude with femate gamete and forms Zygote. This zygote after the secretion of thick wall forms Zygospores.