The answer is the radioactive isotope reacts in the same way as stable isotopes in the chemical reactions in the body.
C-14 and C-12 are carbon isotopes used to measure the approximate age of organic remains. C-12 is stable, and it does not break down into other elements over time. C-14 is not stable. It breaks down into N-14. But, in the body, the radioactive isotope reacts in the same way as stable isotopes in the chemical reactions.
Hey, there!
Question: Which level of classification contains all the others
Answer: 
(
Option B)
Good luck on your assignment and enjoy your day!
~
Answer:
They help our ecosystems and food chains all over the world
Explanation:
Autotrophs are the most important organisms on the planet because they are fundamental to food chains all over the world. They take energy from the environment in the form of sunlight or inorganic chemicals and use it to create fuel molecules like carbohydrates to release the hydrogen atoms that fuel the metabolic process of primary production.
<em>Explanation is in the paragraph above. Hope that helps!</em>