Not all spider bites are bad, in fact, most are not, but there are a few spiders that when they bite, they do incredible damage like the brown recluse below!pider Identification. Spiders can be found living in almost every habitat on earth. The only place that spiders are not found is only the harshest environments on Earth, the North and South poles, the highest mountains and the ocean. Some spiders have been found near the ocean, living in coral near the ocean edge.
A milliliter of blood contains about 5 billion red blood cells, each of which is packed with about 300 million hemoglobin molecules! A milliliter of blood contains about 5 billion red blood cells, each of which is packed with about 300 million hemoglobin molecules!
The normal concentration of hemoglobin in blood is 15.5 grams per deciliter of blood in men, and 14 grams per deciliter of blood in women. (A deciliter is 100 milliliters, or one-tenth of a liter.) Besides carrying oxygen to the cells of the body, the RBCs help to remove carbon dioxide (CO2) from the body. Carbon dioxide is formed in the cells as a byproduct of many chemical reactions. It enters the blood in the capillaries and is brought back to the lungs and released there and then exhaled as we breathe.