A crystal contains a radioactive isotope that has a half-life of 20,000 years. You analyze a sample and find that one-eighth of the isotope remains (12.5%). How old is the sample? How many half-lives have passed?

In one or two, well-crafted paragraphs in your laboratory journal, summarize the process in which normal cells become cancer cells. your paragraph (s) must include each of the terms listed below.

How thick are Saturn's rings? A.) thousands of kilometers B.) a few kilometers C.) hundreds of kilometers D.) a few meters

Is the mode of inheritance of the ABO blood types representative of dominance? of recessiveness? of codominance?

Anatomy question? Which of the descriptions below does not explain the effects of air pollution on the respiratory system? It could restrict air flow through the bronchi. It could disrupt the rate of ventilation.

What enzyme enzyme speeds up the breakdown of fats in food

What is the menstrual cycle and how long does it last?

Six fingered offspring are formed from normal fingered parents. why?

What does the red-shift of galaxies indicate? A. The galaxies are not moving. B. The galaxies are shrinking. C. The galaxies are moving toward each other. D. The galaxies are moving away from each other.

Which scientist contributed to our understanding of infectious disease

Which of the following is NOT a function of the blood. Select one: a. Transportation of oxygen and carbon dioxide. b. Protection against blood loss through monocyte-mediated clotting. c. Transportation of hormones from glands to target cells. d.