In the RNA world hypothesis, DNA replaced RNA in storing genetic information because RNA is ______.

• A. catalyzing chemical reactions
• B. energy storage
• C. storing genetic information
• D. structural support

Answer: (C)

In the RNA world idea, RNA once carried genetic information and also catalyzed reactions. The reason DNA eventually replaced RNA for storing genetic information is that RNA is chemically unstable over time: the 2′-hydroxyl on ribose makes RNA susceptible to hydrolysis and degradation, so it’s not ideal for long-term information storage. DNA is more chemically stable, and its double-stranded form provides redundancy and repair opportunities, making it far better at preserving genetic information across generations. Among the given choices, the statement about RNA’s role in storing genetic information aligns with its historical function in the RNA world, which helps explain why a more stable molecule—DNA—took over that storage task. The overarching point is that stability of genetic storage drives the shift from RNA to DNA.