Which of these processes are necessary for the complete development of male gametophyte from pollen mother cell? 

Microspore mother cell divides via meiosis to produce 4 haploid microspores. Each microspore divides via mitosis to produce one vegetative cell and one generative cell. Each generative cell divides via mitosis to form 2 male gametes. Therefore, for complete development of male gametophyte from pollen grain there is the requirement of one meiosis and two mitosis.