Animal cells do not have a cell wall or chloroplasts but plant cells do. This is just one example there are several ways. <span />
<span>They need to live near to the surface in order to get sunlight and perform photosynthesis.</span>
Hormones contact you through your bodies system to receive feedback from another perspective.
Energy is the capacity of a physical system to perform work. Energy exists in several forms such as heat , kinetic or mechanical energy, light, potential energy , electrical, or other forms. Energy is the ability to do work. Energy sources could be classified as Renewable and Non-renewable.