The DNA structure is made up of molecules called nucleotides
It is not just the muscle cells that respire. All cells in the body need oxygen for respiration and all cells need to get rid of the carbon dioxide that they produce. In the lungs oxygen is taken from air into the blood and the blood transports the oxygen to the cells in all tissues of the body.As the muscles use the oxygen up,carbon dioxide is produced and absorbed into the blood. And this de-oxygenated blood is pumped back to the heart then on to the lungs. The lungs get rid of this carbon dioxide, and breathe in more oxygen.
Hope this answered your question.
Human activities such as pollution , like trash , or boat oil can effect the waters that house 100 of creature and as for nitrogen cycle things like forest burning and fossil fuel combustion can result in the increased deposition of nitrogen from atmospheric sources
Is silk softer than satin can be answered by science
