Why do scientists need a way to sort, or classify, living things? What method do they use to do this?

How is the life cycle of seedless vascular plants different from the life cycle of nonvascular plants? the adult form of each seedless vascular plant has xylem and phloem. the gametophyte stage is lacking in the life cycle of seedless vascular plants. the sperm of seedless vascular plants do not need to swim in water. the zygote of each seedless vascular plant forms before the egg is fertilized. asap