Why is earth considered an open system and a closed system?

The earth is a closed system because only energy is naturally transferred outside the atmosphere.

Explanation:

All systems inside the Earth, on the other hand, are open systems as both energy and matter can be transferred between the systems and their surroundings.

Got this from Google hope this helps 

The monomers of DNA and RNA are nucleotides, which are made up of a phosphate group, a five-carbon sugar and a nitrogenous base. In DNA, the nitrogenous basesare adenine, cytosine, guanine and thymine. In RNA, the nitrogenous bases areadenine, guanine, cytosine and uracil.