Circulatory system in the body helps in the transport of oxygen, nutrients and other important substances in the body.
Single loop circulatory systems involves blood passing through the heart only once on each circuit around the whole of the blood circulation system of the animal.
Double loop means there are two loops in our body in which blood circulates. One is oxygenated which means oxygen rich and the other is deoxygenated, which means it has little to no oxygen, but a lot of carbon dioxide.
Photo Synthesis would be as plants grow from the sun or gain energy from the sun, where as Cellular Respiration is when cells divide into two or more. (I believe)
