AP BIOLOGY

Detailed explanation-1: -Short day plants require light below the critical photoperiod to induce flowering. They usually flower during the seasons when the days are of short duration, such as during the summer or fall. A continuous period of darkness is necessary for flowering in the short day plants.

Detailed explanation-2: -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-3: -Long-day plants flower when they are exposed to day length LONGER than the critical minimum period. Short-day plants are also called as Long-night Plants. Long-day plants are also called as Short-night Plants. Short-day plants usually flower in the early spring or autumn.

Detailed explanation-4: -Photoperiodism in Short Day Plants These plants must be exposed to continuous long periods of darkness in order to flower. If they are not exposed to continuous darkness, the plant will continue to grow and put out vegetation but it will not reproduce.

Detailed explanation-5: -Short day plants are also called long night plants because these plants require short days but long nights to be able to flower properly. The nights must be long and uninterrupted for them to flower. Such a dependency on the length of the day is called photoperiodism.