Answer:
Poinsettia leaves change color from green to red if they experience fewer than 8 hours of continuous daylight within 24 hours
Step-by-step explanation:
Hypothesis is defined as a statement which we are trying to prove and make a theory out of it in case hypothesis is proved after multiple experiments and verified within a substantially long timeframe.
In this case, we know that some poinsettia plants have green leaves that turn red during the short daylight periods of winter. This means that the trend was noticed specifically when the amount of daylight during the day was minimal.
We are, therefore, testing the influence of continuous daylight on the color of the leaves of poinsettia. It would require multiple experiments to find the time of continuous daylight required to keep poinsettia leaves green. Let's assume, for example, that the average daylight in winter lasts for 8 hours. Our hypothesis could then be that 'poinsettia leaves change color from green to red if they experience fewer than 8 hours of continuous daylight within 24 hours'.