How come an animal's carbon-14 levels do not start to decrease until it dies?
A) because it constantly replenishes its carbon-14 supply by eating plants with carbon-14 in them
B) because it constantly replenishes its carbon-14 supply by breathing air with carbon-14 in it
C) because it is constantly being bombarded with cosmic rays
D) carbon-14 only starts to decay after the animal dies
E) The carbon-14 levels do not decrease because the carbon-13 in its skin protects it from cosmic rays.
A
You might also like to view...
Why is chemistry described as the "central science"?
What will be an ideal response?
What factors can affect the value of the environmental lapse rate?
What will be an ideal response?
Complete the concept map by selecting the correct responses from the lists provided. 
Complete the concept map by selecting the correct responses from number 2.
A. Epicenters B. Faults C. Coasts D. Cliffs
Invasive species typically have rapidly increasing population sizes because
A. they have very effective mechanisms for dispersal. B. they can live in a variety of habitats. C. they have few predators or diseases in their new location. D. All of the above are correct. E. None of the above is correct.