AP BIOLOGY

Detailed explanation-1: -The different features associated with long-day plants are the need for less darkness, flowering in spring, and the requirement of a short night. Thus, 8 hours of dark period is not exceeding the critical night to prevent flowering. Therefore, the given statement is false.

Detailed explanation-2: -Long-day plants flower and grow when the daylight they obtain is more than their critical (required) photoperiod, like in summer season. They need more light than short-day plants and usually flower when the temperature becomes warmer. Examples of long day plants are spinach, lettuce, radish, sugar beet etc.

Detailed explanation-3: -When the length of night is longer than the critical dark period, short-day plants are induced to flower and long-day plants never flower. In a natural setting, critical dark period is 24 hours minus critical daylength.

Detailed explanation-4: -In short day plants, the dark period is critical and so it must be continuous for a certain period. These plants are also called as long night plants.

Detailed explanation-5: -Long Day Plants: They require the periodic exposure of light exceeding the critical period to induce flowering. Short Day Plants: They require the periodic exposure of light less than the critical period to induce flowering. Day-neutral Plants: The flowering in many plants does not depend on the photoperiod.