Which of the following is most widely considered to have been the first genetic material on Earth?

• A. DNA
• B. Proteins
• C. Polysaccharides
• D. RNA

Answer: (D)

Verified step by step guidance

1. Understand the question is asking about the identity of the first genetic material on Earth, which is a fundamental concept in molecular evolution and the origin of life.
2. Recall that genetic material is defined as the molecule capable of storing and transmitting genetic information necessary for inheritance and biological function.
3. Consider the properties of each option: DNA is stable and stores genetic information in modern organisms; proteins perform catalytic functions but do not store genetic information; polysaccharides are structural or energy storage molecules, not genetic material.
4. Recognize that RNA has the unique ability to both store genetic information and catalyze chemical reactions (ribozymes), supporting the RNA world hypothesis as the earliest genetic system.
5. Conclude that RNA is most widely considered the first genetic material because it can carry information and catalyze its own replication, bridging the gap between genetic storage and enzymatic function.