Which hypothesis proposes that RNA could have been the first self-replicating precursor to life on Earth?

• A. Panspermia hypothesis
• B. Endosymbiotic theory
• C. Iron-sulfur world hypothesis
• D. RNA world hypothesis

Answer: (D)

Verified step by step guidance

1. Understand the context of the question: The problem is asking about a hypothesis that explains the origin of life on Earth, specifically focusing on the role of RNA as a self-replicating molecule.
2. Review the RNA world hypothesis: This hypothesis suggests that RNA was the first self-replicating molecule capable of storing genetic information and catalyzing chemical reactions, making it a precursor to life.
3. Compare the RNA world hypothesis to other options: The Panspermia hypothesis suggests life originated elsewhere in the universe and was transported to Earth, the Endosymbiotic theory explains the origin of eukaryotic cells, and the Iron-sulfur world hypothesis proposes life began in hydrothermal vents with chemical reactions involving iron and sulfur.
4. Identify why the RNA world hypothesis is correct: RNA has the unique ability to act as both a genetic material and a catalyst (ribozymes), which supports the idea that it could have been the first self-replicating molecule.
5. Conclude that the RNA world hypothesis is the most plausible answer based on its explanation of RNA's dual role in early life processes.