How are the gametophyte and sporophyte stages different in ferns?

Ferns exhibit an alternation of generations between two distinct stages: the sporophyte and the gametophyte.1

The Sporophyte Stage

The sporophyte is the dominant, asexual generation—the familiar fern plant consisting of stems, leaves, and roots. Its cells contain two sets of chromosomes. Mature sporophytes produce spores within specialized organs called sporangia, which are often clustered on the undersides of fronds.213

The Gametophyte Stage

The gametophyte, or prothallium, is a small, typically heart-shaped sexual plant that develops from a germinated spore. Unlike the sporophyte, it is haploid (containing one set of chromosomes) and is usually only one cell layer thick. It produces gametes—sperm and eggs—via antheridia and archegonia. Once fertilization occurs, the resulting zygote develops into a new sporophyte, and the short-lived gametophyte typically withers and dies.2413