<span>Pulmonary vein
Pulmonary circulation is the movement of blood starting from the heart, where deoxygenated, or carbon dioxide-filled, blood leaves from the right ventricle and through the pulmonary valve, then into the left and right pulmonary arteries and arrives at the lungs. During the process of respiration, the carbon dioxide is released and oxygen is added to the blood. </span>
It began 3.5 billion years ago
Humus is a dark organic matter that is an important part of your soil
Humus consists of decomposing organic material. The process of creating humus is called Humification: decomposition of o<span>rganic matter into smaller and smaller molecules by the micro-organisms in the soil (mostly bacteria and fungi).</span>
A mutation in DNA affects the entire protiens synthesis process by producing the incorrect amino acids in the wrong places, causing issues with the ability of the organism to survive depending on what the protein is in charge of.
