Even after killing the generative cell with a laser beam, the pollen grain of a flowering plant germinates and produces normal pollen tube because

laser beam stimulates pollen germination and pollen tube growth

the laser beam does not damage the region from which pollen tube emerges

the contents of killed generative cell permits germination and pollen tube growth

the vegetative cell has not been damaged

Solution

the vegetative cell has not been damaged

During the post-pollination development, germination of pollen grain takes place. The pollen grain absorbs water and nutrients on the stigma from the stigmatic secretion through its germ pores. The tube or vegetative cell enlarges and comes out of the pollen grain through one of the germ pores or germinal furrows to form a pollen tube. Generative cell does not produces pollen tube instead it passes into the pollen tube and divides into 2 male gametes. Thus even after killing the generative cell with a laser beam, the pollen grain produces normal pollen tube because the vegetative cell has not been damaged.