Answer:
Step-by-step explanation:
Plants that require a certain length of darkness to flower are called short-day plants, while those that require a certain length of light are called long-day plants. There are also plants that are day-neutral, meaning that their flowering is not affected by the length of day or night.
In short-day plants, the length of the night period triggers the production of a hormone called florigen, which promotes flowering. In long-day plants, the length of the day period promotes the production of florigen. The production of this hormone is thought to be regulated by a protein called CONSTANS, which is produced in response to changes in light duration.
It's important to note that the exact mechanisms of photoperiodism can vary between plant species, and there are also other environmental factors that can influence the timing of flowering, such as temperature and nutrient availability.