Answer: Melanin is a pigment in the skin of animals (including humans). Melanin is essentially what allows the human body (the skin) to darken when sunlight (or, ultraviolet rays) hits it. The skin absorbs the UV rays and the melanin allows the skin to become darker.
A simpler definition:
Any of a group of naturally occurring dark pigments, especially the pigment found in skin, hair, fur, and feathers.
Answer: The primary function of insurance company is to provide protection from adverse events. The insurance companies accept premium payments in exchange for companies in the eventthat certain specified but undesirable, event occure.
The primary function of iron in a human body is to supply the blood flow with oxygen. Iron is a powerful oxygen absorber when suspended in a liquid such as blood.
Iron is essential to good health. Most iron in the body is contained in haemoglobin and myoglobin, the red pigments that carry oxygen. It also occurs as part of enzymes involved in energy production. A deficiency of iron results in anaemia, a lowering of haemoglobin concentration in the blood. The muscles and tissues are starved of vital oxygen, we feel tired and lethargic, and less inclined to exercise. Other more specific problems may include a sore tongue, cracks at the corner of the mouth, and nails that lack their usual pink flare. Heavy endurance training and bleeding (including menstrual bleeding) can increase the risk of iron deficiency and the need for iron therapy (increased iron intake by dietary adjustment and supplementation). Ten to fifteen percent of women between the ages of 13 and 45 lose more iron in menstrual bleeding than they acquire throughout the month from foods. Therefore, they probably require iron supplements to prevent iron deficiency.
Answer: I think you mean lymphocytes. The B and T cells are lymphocytes that are responsible for destroying unwanted viruses and bacteria in your body. They are cells of the immune system. These cells are found in the lymph nodes.
Answer: The primary function of platelets is to from blood clots. The formation of these blood clots help to control bleeding so there is not too much blood loss. To form a blood clot, platelets clump together using fibrinogen as an adhesive.