The correct answer is B. controlling the flow of blood to the skin
The more blood there is, the more heat there will be because of blood. An easy example is when someone's ears get all red due to a blood rush to the ears. At that time, ears are also very warm.
DNA<span> is a long polymer with deoxyribose and phosphate backbone. Having four different nitrogenous bases: adenine, guanine, cytosine and thymine. </span>RNA<span> is a polymer with a ribose and phosphate backbone. Four different nitrogenous bases: adenine, guanine, cytosine, and uracil.</span><span />
Breathing starts at the nose and mouth. You inhale air into your nose or mouth, and it travels down the back of your throat and into your windpipe, or trachea. Your trachea then divides into air passages called bronchial tubes.
For your lungs to perform their best, these airways need to be open during inhalation and exhalation and free from inflammation or swelling and excess or abnormal amounts of mucus.
The LungsAs the bronchial tubes pass through the lungs, they divide into smaller air passages called bronchioles. The bronchioles end in tiny balloon-like air sacs called alveoli. Your body has over 300 million alveoli.
The alveoli are surrounded by a mesh of tiny blood vessels called capillaries. Here, oxygen from the inhaled air passes through the alveoli walls and into the blood.
After absorbing oxygen, the blood leaves the lungs and is carried to your heart. Your heart then pumps it through your body to provide oxygen to the cells of your tissues and organs.
As the cells use the oxygen, carbon dioxide is produced and absorbed into the blood. Your blood then carries the carbon dioxide back to your lungs, where it is removed from the body when you exhale.
