AP BIOLOGY

Detailed explanation-1: -Long-day plants need short periods of darkness in order to flower (less than 12 hours). They usually bloom in the summer. Day-neutral plants are not dependent on day and night length in order to bloom.

Detailed explanation-2: -Other plants require only a short night to flower. These are termed “long-day” plants. These bloom only when they receive more than 12 hours of light. Many of our summer-blooming flowers and garden vegetables are long-day plants, such as asters, coneflowers, California poppies, lettuce, spinach and potatoes.

Detailed explanation-3: -A plant that requires a long period of darkness is termed a “short-day” (long-night) plant. Short-day plants form flowers only when day length is less than about 12 hours. Many spring-and fall-flowering plants are short-day plants, including chrysanthemums, poinsettias and Christmas cactus.

Detailed explanation-4: -The short day plants are those plants that bloom flower in day length shorter than the critical point. The long day plants are those that bloom when they are exposed to days longer than the critical point. 2. The short day plants need continuous dark periods.

Detailed explanation-5: -Long days also means shorter nights. Therefore, these plants are called Long Day Plants or Short Night Plants.