How canna person donate blood and never run out of it? a)blood componentes are continuously pumped by the heart. b)blood componentes are continuously circulated through the blood vessels. c)blood componentes are continuously produced in the bone marrow. d) blood componentes are continuously digested by enzymes.

For a comparative or experimental investigation, scientists often make a testable about a scientific question, and then they test it in the investigation. a.control b.hypothesis c.procedure d.system

Which heredity condition causes a buildup of mucus in lungs and pancreas? a. cystic fibrosis b. heart disease c. huntington's disease d. sickle cell anemia

Water changes bacteria in the soil converts this nutrient into a usable form. plants take up the usable nutrient through the soil and assimilate it into proteins, making it part of the plant. an animal eats the plants, and the nutrient becomes part of the animal. when the animal dies, it decomposes, returning the nutrient back to the soil. which cycle is being described? water cycle carbon cycle nitrogen cycle phosphorous cycle