Question

question 11
carbon dioxide containing carbon-14 is introduced into a balanced aquarium ecosystem. after several weeks, carbon-14 will most likely be present in
1 the plants, only
2 the animals, only
3 both the plants and animals
4 neither the plants nor animals

Explanation:

In an aquarium ecosystem, plants perform photosynthesis and take in carbon dioxide (including carbon - 14 - labeled CO₂) to make organic compounds. Then, animals in the ecosystem eat the plants (or other animals that ate the plants), so the carbon - 14 will be transferred to the animals as well. So carbon - 14 will be present in both plants and animals. Option 1 is wrong because animals will get the carbon - 14 from plants. Option 2 is wrong as animals can't get carbon - 14 directly from CO₂, they get it from plants. Option 4 is wrong as both plants and animals will have carbon - 14.

Answer:

1. both the plants and animals