What is Plant Life Cycles?

A plant life cycle includes growth and reproduction as well as transitions between reproductive stages. The stages’ visibility and dominance differ among plant groups.

What is alternation of generations?

Many plant life cycles alternate between a haploid gametophyte and a diploid sporophyte. The gametophyte produces reproductive cells; fertilization creates a zygote that develops into the sporophyte. The sporophyte produces spores by meiosis, and those spores can develop into new gametophytes. In seed plants, the sporophyte is the large, visible stage, such as a tree or flowering plant, while gametophytes are greatly reduced. In mosses, the green and visible plant is usually the gametophyte. These differences are central to understanding plant reproduction.

Annual, biennial, and perennial plants

In horticulture, plants are also classified by lifespan as annual, biennial, or perennial. Annuals may complete their life cycle in one growing season; biennials often grow leaves and roots in the first period and flower and set seed in the next. Perennials can live for multiple years under suitable conditions. These terms describe an individual’s growth and reproductive pattern, not the full evolutionary life cycle of plants. Climate, cultivation, and the length of the local growing season affect how the categories appear in practice. Understanding the life cycle helps determine sowing, pruning, and seed-collection times.