One possible reason that stands out is that the sporophyte phase has an
advantage over the gametophyte phase because it is diploid rather than haploid.
Having two sets of genes can avoid expression of deleterious traits.
The seed plant pattern of large sporophyte is a very effective system. Remember
the key features:
1. Large sporophyte nurtures the tiny female gametophytes.
2. There are millions of tiny male gametophytes (pollen) that can be carried
great distances, either by wind or by animals.
3. New sporophytes arise from very mobile, usually very tough, seeds that
contain energy supply and tiny plant in suspended animation.
The sporophyte generation has vascular tissues.
The Sporophyte life cycle is the dominant stage in Ferns (vascular non-seed plants)
Having a vascular system and a dominant sporophyte generation enable ferns to be more diverse and widespread
Mosses are non-vascular plants whereas ferns are vascular. In ferns Sporophyte is dominant but in mosses gametophyte is dominant generation. Ferns have definite roots but in mosses leaves and roots are mostly false.
In a moss, gametophytes are photosynthestic.
According to Wikipedia:"Vascular plants are distinguished by two primary characteristics:Vascular plants have vascular tissues which distribute resources through the plant. This feature allows vascular plants to evolve to a larger size than non-vascular plants, which lack these specialized conducting tissues and are therefore restricted to relatively small sizes.""In vascular plants, the principal generation phase is the sporophyte, which is usually diploid with two sets of chromosomes per cell. Only the germ cells and gametophytes are haploid. By contrast, the principal generation phase in non-vascular plants is the gametophyte, which is haploid with one set of chromosomes per cell. In these plants, only the spore stalk and capsule are diploid."
Sporophyte is the dominant generation.
The Sporophyte is the dominant generation of the club moss, which is a Lycopodium. Also, club mosses are vascular plants, and the diploid generation is dominant for vascular plants.
In vascular plants, the principal generation phase is the sporophyte, which is usually diploid with two sets of chromosomes per cell. By contrast, the principal generation phase in non-vascular plants is usually the gametophyte, which is haploid with one set of chromosomes per cell.http://en.wikipedia.org/wiki/Vascular_plants
The Sporophyte life cycle is the dominant stage in Ferns (vascular non-seed plants)
The gametophyte of moss is the dominant structure
Having a vascular system and a dominant sporophyte generation enable ferns to be more diverse and widespread
gymnosperms
Mosses are non-vascular plants whereas ferns are vascular. In ferns Sporophyte is dominant but in mosses gametophyte is dominant generation. Ferns have definite roots but in mosses leaves and roots are mostly false.
Ferns have a dominant sporophyte and a reduced gametophyte. As for moss, it depends on the type. If referring to mosses under the phylum Bryophyta (these are the nonvascular mosses) they have a dominant gametophyte. If referring to mosses under seedless vascular category, such as club mosses in the phylum Lycophyta, these plants have a dominant sporophyte and a reduced gametophyte.
In a moss, gametophytes are photosynthestic.
According to Wikipedia:"Vascular plants are distinguished by two primary characteristics:Vascular plants have vascular tissues which distribute resources through the plant. This feature allows vascular plants to evolve to a larger size than non-vascular plants, which lack these specialized conducting tissues and are therefore restricted to relatively small sizes.""In vascular plants, the principal generation phase is the sporophyte, which is usually diploid with two sets of chromosomes per cell. Only the germ cells and gametophytes are haploid. By contrast, the principal generation phase in non-vascular plants is the gametophyte, which is haploid with one set of chromosomes per cell. In these plants, only the spore stalk and capsule are diploid."
Club mosses (Phylum Lycopodophyta) and horsetails (Phylum Equisetophyta) are similar to ferns (Phylum Pteridophyta) in that they; - do not produce seeds, only spores - have stems that are unstrengthened by wood (evolved first in the more advanced gymnosperms) - have a dominant sporophyte generation - do have vascular tissue (not as advanced as seed plants but there nonetheless) - do not produce flowers (flowers evolved first in angiosperms)