Gametophyte
/ɡəˈmiːtəˌfaɪt/
Definition
Gametophyte is the haploid stage in a plant’s life cycle, meaning its cells carry one set of chromosomes. It develops from a spore and produces sex cells by mitosis, unlike the diploid sporophyte, which produces spores. In mosses, the gametophyte is the visible leafy plant, while in ferns and seed plants it is much smaller and often short-lived.
Role in Plant Biology
- Alternation of generations: In land plants, gametophyte is one half of the life cycle, alternating with the spore-producing sporophyte. This pattern is central to how plants reproduce and develop across major plant groups.
- Different prominence by plant group: In mosses and many liverworts, gametophyte is the main visible plant body. In ferns and seed plants, it is much smaller, showing an important evolutionary shift in plant life cycles.
- Link to fertilization: Gametophyte is the stage that produces eggs or sperm, so successful fertilization depends on its formation and function. In bryophytes and ferns, this helps explain why free water is often needed for sperm movement.
- Hidden forms in seed plants: In flowering plants and conifers, gametophyte is highly reduced and develops inside reproductive structures. Pollen and the embryo sac are the male and female forms, which is why this stage is usually not noticed by gardeners.
Related Terms
Sporophyte
Sporophyte refers to the diploid, spore-producing stage in a plant’s life cycle. It develops from the fertilized egg…
Gamete
Gamete refers to a plant reproductive cell with one set of chromosomes, called haploid. In seed plants, the male gamete…
Spore
Spore refers to a microscopic reproductive cell that can grow into a new organism without fusing with another cell. In…
Sporangium
Sporangium is a spore-producing structure found in plants, algae, fungi, and some plant-like organisms. In land plants…
Microspore
Microspore refers to the small spore produced in the male sporangia of seed plants and many other land plants. It is…
Megaspore
Megaspore refers to the larger of the two spore types produced by heterosporous plants and seed plants. It forms inside…