Final answer:
The leading hypothesis for the first system of inheritance is centered on self-replicating RNA molecules aided by ribozymes, known as the RNA world hypothesis. This hypothesis addresses the 'chicken-and-egg' dilemma by proposing that RNA could function both to store genetic information and to catalyze chemical reactions. Evidence from ribozymes and studies on RNA catalyst evolution supports this model. The correct option is C.
Step-by-step explanation:
The current leading hypothesis about the first system of inheritance in the earliest life forms is C. self-replicating RNA molecules aided by ribozymes. This theory is known as the RNA world hypothesis. It suggests that RNA was likely the first organic molecule to evolve because it can encode genetic instructions like DNA and certain RNAs can carry out chemical reactions like proteins. Thus, RNA can solve the 'chicken-and-egg' problem of which of these two molecules came first. The RNA world hypothesis also supports the idea that before proteins and DNA evolved, there were RNA molecules that could self-replicate and catalyze biological reactions, essential functions for early forms of life.
Further evidence in support of the RNA world hypothesis includes the observation that ribozymes and ribonucleoprotein structures exist today, pointing to a legacy from an earlier RNA-based chemistry. Additionally, studies involving artificial ribozyme evolution have shown that RNA catalysts can become more efficient replicators over time.
Once molecules like RNA began self-replication, natural selection would have come into play, favoring more efficient reproducers, and this would pave the way for the development of more complex life forms. Important components of the modern cell, such as ribosomes, are partly made of RNA, bolstering the argument for RNA's central role in early life forms.