Bone: The hard, rigid form of connective tissue constituting most of the skeleton of v â¦ ertebrates, composed chiefly of calcium salts.Cartilage: Tough, elastic, fibrous connective tissue that is a major constituent of embryonic and young vertebrate skeletons.
People with the blood type AB are in the greatest demand for plasma donation. Though they make up just 4 percent of the population, their plasma is universal, which means it can be used by anyone. At noncommercial donation sites, people can donate plasma every 28 days, up to 13 times a year. To learn more about donating blood, visit the American Red Cross website.
You may donate whole blood once every 56 days, which allows plenty of time for your red cells to be replenished. Platelet (apheresis) donors may donate more frequently -- as often as once every seven days and up to 24 times per year. This is because the body replenishes platelets and plasma more quickly than red cells. Platelets will return to normal levels within about 72 hours of donating.