How can a plant know that winter has passed and adjust the expression of its gene to produce flowers in the spring?

Many factors work together to "tell" a plant when it is time to flower, including the amount of food and water available, light, temperature, and a plant's age. But just how a plant senses many of these things remains a puzzle. To begin with, food and water regulate flowering time in many plants.

answer; i believe that the correct answer is ; males are hemizygous for the x chromosome;