Question

Some scientists have proposed that the earliest forms of life may have existed in an "RNA World" where RNA was both the genetic material and responsible for enzymatic activity. Imagine that you have recreated such a life form. What would demonstrate that RNA, but not protein or DNA, is necessary and sufficient for these functions?
(A) The organism lives and replicates despite RNase and DNase treatment, but the organism dies when treated with protease.
(B) The organism lives and replicates despite protease and DNase treatment, but the organism dies when treated with RNase.
(C) The organism lives and replicates despite protease treatment, but the organism dies when treated with DNase and RNase.
(D) The organism lives and replicates despite DNase treatment, but the organism dies when treated with RNase and protease.

Answer 1

Answer:

(B) The organism lives and replicates despite protease and DNase treatment, but the organism dies when treated with RNase.

Explanation:

DNA is the genetic material in present day organisms while some of the proteins serve as enzymes and catalyze the metabolic reactions.

An organism having RNA with the ability to serve as genetic material would not require DNA to survive. Likewise, if RNA molecules in these organisms also serve as the enzyme, proteins would not be required for survival.

Therefore, when treated with DNase and protease that digest the DNA and proteins respectively, these organisms would be able to survive. However, treatment with RNase enzymes that digest the RNA would kill them as RNA was their biocatalyst and genetic material.