Radioactive isotopes are biological tools that are often used to
A. measure the size of fossils.
B. detect brain tumors.
C. build up a store of calcium in a cell.
D. increase the pH of blood.
Answer:B
Radioactive isotopes are biological tools that are often used to
A. measure the size of fossils. B. detect brain tumors. C. build up a store of calcium in a cell. D. increase the pH of blood.