By intruding mutations, which are the ultimate source of biological diversity. I think this is it.
No idea about the scientific reasoning, but the leaves of the plant are where the most photosynthesizing has to happen. In order for the plant to get energy it has to absorb the most light. So it creates broad leaves. The reason they are green is because chloroplasts are green. I believe that the cells in the leaves have more chloroplasts so that they can catch more sunlight.<span />
They are both the building blocks of life
The sensory receptors located on a frog's head assist it in the water through protection and flotation. The receptors hold the frogs head above the water, and the frog uses this as an advantage to see if there is any predators or prey around to help it survive. Hope this helps!