Practice question · Multiple choice
Why does the RNA world hypothesis resolve the chicken-and-egg problem of DNA and protein?
Hints
- The problem is that DNA needs protein and protein needs DNA.
- A single molecule doing both jobs breaks the circle.
Show the answer
B. RNA can both carry information and catalyse reactions, so it needs no partner
Why
The deadlock exists only if information and catalysis must live in different molecules. RNA does both, ribozymes are real catalysts, so a self-sufficient starting point becomes possible. RNA is in fact less stable than DNA, which is why DNA later took over storage.
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More questions on The Origin of Life and the RNA World
- Place these stages of early molecular evolution in the order the RNA world hypothesis proposes.
- A hypothetical genetic code uses 4 bases and codons of length 2. How many distinct codons does it have?
- The Last Universal Common Ancestor (LUCA) marks a genealogical bottleneck rather than the inception of…
- Which observations support the idea that RNA preceded DNA and protein?
- The genetic code is essentially the same in bacteria, plants and animals.
- Sort each molecule by the role the RNA world hypothesis assigns it in modern cells.