The carbon cycle is one of earths natural resources that enables all living organisms to inhabit the planet. For example, with out this vital resource we would run out of oxygen. Flora (plants and trees) use the carbon that is a by product of cellular respiration by fauna (humans and animals) to reproduce oxygen and this cycle continues. which is what keeps all living organisms in harmony and alive.
double stranded molecule does not describe the structure of RNA. Most RNA are single stranded with partial double stranded regions. RNA has basic component as the DNA that is have four nitrogenous base, contain phosphate group and have 5 carbon sugar.