[Campbell Biology P.815] A gardener grows carrots, which are biennials. After one season, th... | Practice Question

A gardener grows carrots, which are biennials. After one season, the carrot roots are too small. The gardener leaves the crop in the ground for a second year, expecting the roots to grow larger. Is this a good idea? Explain.

  • A: Yes, because biennials focus on vegetative growth, including root enlargement, in their second year.
  • B: No, because biennials complete their life cycle by flowering and producing seeds in the second year, diverting energy away from root enlargement.
  • C: Yes, as long as the gardener provides more fertilizer, the roots will continue to grow larger indefinitely.
  • D: No, because biennials are typically annuals in disguise and will die after the first year if not harvested.

Explanation

Carrots are biennials, meaning they complete their life cycle in two growing seasons. The first season is typically for vegetative growth, accumulating energy in the root. The second season is for flowering and producing seeds, at which point the plant diverts stored energy to reproduction, and the root will not continue to grow larger. In fact, it may even shrink as stored reserves are used.