Sporophyte vs Gametophyte
The reproduction of plants can be categorized into two different phases, asexual reproduction and sexual reproduction. During the evolution of plant life, development of the reproduction system of a plant was varied depending on the complexity of the plant category. Six different plant categories were studied in the evolution of plants. Those were Bryophytes, Psilophytes, Lycophytes, Sphenophytes, Pteridophytes and Spermatophytes. When considering all six categories, the reproduction systems were different from each other. In most plants, the sexual reproduction occurs by two different phases called meiosis and fertilization. By meiosis and fertilization, life cycle of a plant divides into sporophyte generation and gametophyte generation. During the reproduction process, these two phases taking place alternatively and hence called Alternation of Generations. This gives rice to the continuous occurence of a plant life cycle.
In the gametophyte generation, gametes are formed. This phase begins with the formation of spores. Production of spores taking place by meiosis and the spores produced are haploid. Spores undergo mitosis and the cells of the formed multicellular structure are also haploid. By the process called mitosis, this multicellular structure produces haploid male and female gametes (egg and sperms). When the male and female gametes are produced, they fused together, fertilized and give rise to the diploid zygote.
The beginning of the diploid sporophyte generation starts with the formation of this diploid zygote. The zygote grows into a diploid sporophyte, which forms haploid spores in the sporophyte generation. By the process of meiosis which reduces the number of chromosomes in a cell to half of its parents’ cells, the diploid sporophyte produces haploid spores. These haploid spores eventually grow as multicellular, haploid gametophytes which give rise to the next gametophyte generation.
What is the difference between Sporophytes and Gametophytes?
• Sporophyte phase produces spores, while gametophyte phase produces gametes (egg and sperms).
• Therefore, sporophyte phase is asexual, while gametophyte phase is sexual.
• Sporophyte is a diploid phase (2N) due to the formation of zygote, while gametophyte is a haploid phase (N) due to the occurrence of meiosis.
• The diploid zygote is the first cell in a sporophyte generation, and the haploid spore is the first cell in the gametophyte generation.
• In Bryophytes, Psilophytes, and Lycophytes, the gametophyte stage is larger, and the sporophyte stage is growing on the gametophyte stage.
• In angiosperms, the sporophyte phase is the larger, while the gametophyte phase is smaller.