Final answer:
In mosses, the fusion of gametes leads to the diploid sporophyte generation. The sporophyte grows from the dominant gametophyte stage and is nourished by it until it can produce spores to complete the life cycle.
Step-by-step explanation:
In mosses, the fusion of gametes (syngamy) leads to the formation of the diploid sporophyte generation. The life cycle of a moss consists of an alternation between two main stages: the haploid gametophyte and the diploid sporophyte. When male and female gametes fuse during syngamy, the result is a zygote that develops into the sporophyte stage. In mosses, the gametophyte stage is often the most visible and dominant phase of the life cycle, primarily responsible for photosynthesis and environmental interaction.
The gametophyte produces gametes by mitosis, and these gametes unite to form a new diploid organism, the sporophyte, which grows out of the gametophyte. The sporophyte is dependent on the gametophyte for nutrients as it matures and eventually produces spores through meiosis, completing the cycle by giving rise to a new generation of gametophytes.
This pattern of alternating generations, where the haploid and diploid phases follow each other, is a key characteristic of the plant kingdom, and it can be seen clearly in the life cycle of mosses. The gametophyte is haploid, meaning it contains only one set of chromosomes, while the sporophyte is diploid, with two sets of chromosomes.