The opening or closing of the stomata is regulated in the plant by environmental factors such as light and water availability. In cases of lack of humidity, the stomas are closed preventing water losses in the plant. This also prevents the exchange of gases and the entry of atmospheric carbon dioxide necessary for plant nutrition through the process of photosynthesis.
Water molecules in the solid state, such as in ice and snow, form weak bonds (called hydrogen bonds) to one another. These ordered arrangements result in the basic symmetrical, hexagonal shape of the snowflake.
