What term describes plants that complete their life cycle within one year?

The term that describes plants completing their life cycle within one year is "annuals." These plants germinate from seed, grow, flower, produce seeds, and die all within the same growing season, typically aligned with a single year. Annuals are crucial in various ecosystems and gardens because they can produce abundant blooms and fruits quickly, serving important roles in stabilizing soil and providing food sources for pollinators.

Biennials, in contrast, have a life cycle that spans two years, where they typically germinate and grow during the first year and bloom and set seeds in the second. Perennials are plants that live for more than two years, often going through cycles of growth that include periods of dormancy. Winter annuals are a specific type of annuals that germinate in the fall, grow over the winter, and flower in the spring, but they still fit within the broader definition of annuals as they complete their life cycle in one growing season.

Thus, the correct identification of annuals reflects a fundamental concept in plant biology and ecology, emphasizing their rapid lifecycle and their profound impact on seasonal landscapes.