Final answer:
In vascular plants, the dominant life cycle stage is the sporophyte, which offers advantages in adaptation and spore dispersal compared to the gametophyte stage in bryophytes.
Step-by-step explanation:
In contrast to bryophytes, in vascular plants the dominant stage of the life cycle is the sporophyte. Vascular plants have evolved a more complex life cycle where the sporophyte generation is more developed and remains independent throughout its lifecycle. In bryophytes, such as mosses and liverworts, the gametophyte is the dominant stage and the sporophyte is often attached and dependent on the gametophyte for nutrition. However, as plants evolved into vascular plants such as ferns, clubmosses, and seed plants, there was a shift towards a dominant sporophyte stage.
The dominant sporophyte stage in vascular plants allows for greater adaptation to land environments, as it is not tied to water for fertilization as much as the gametophyte stage is. The sporophyte generation also helps in the widespread dispersal of spores, which contributes to the success of the species in various terrestrial habitats. Therefore, the answer is that the dominant stage in vascular plants is the sporophyte.