What is the second law of thermodynamics, in terms of heat/energy?

The Second Law of Thermodynamics says that processes that involve the transfer or conversion of heat energy are irreversible. ... The Second Law also states that there is a natural tendency of any isolated system to degenerate into a more disordered state.

Explanation:

the leaf is an organ of a typical plant, and the main functions are to complete photosynthesis and allow the plant to exchange gas, just like how we have the respiratory system. leaves have the stomata, which collects maintains co2 and o2 levels. this is necessary for cell metabolism. the leaf also collects sunlight using chloroplasts. succinctly, leaves own a pivotal role in sustaining plant life.