What defines biennial plants?

• A. They spread by seed and cut root segments
• B. They complete their life cycle in two growing seasons
• C. They grow taller than 10 feet
• D. They produce spores rather than seeds

Answer: (B)

Biennial plants are characterized by completing their life cycle in two growing seasons. In the first year, they typically focus on vegetative growth, developing a strong root system and foliage. During the second year, they flower, produce seeds, and then die. This distinct cycle differentiates biennials from annuals, which complete their life cycle in one season, and perennials, which live for multiple years.

In contrast, the other options do not capture the essential characteristic of biennials. Biennials do not primarily spread by root segments, nor is their defining trait related to height or spore production, which belongs to different types of plant reproduction. The focus on a two-year life cycle is the key identifying feature that distinguishes biennial plants from others in the plant life cycle spectrum.