Are you sure these are the only answer choices? I believe the answer would be Hippocampus, but it's not up there.
Answer:
Your answer is photosynthesis.
Structurally, DNA and RNA are nearly identical. However, there are three fundamental differences that account for the very different functions of the two molecules. RNA has a ribose sugar instead of deoxyribose sugar like DNA.
Their would be alot of mutations in genes. Also, we wouldn't be able to function properly.
