Final answer:
The term for an RNA molecule with catalytic activity is a ribozyme. Ribozymes are crucial in cellular processes and were instrumental during the hypothesized RNA World, acting as early biological catalysts before proteins took over these functions. The RNA-first hypothesis suggests ribozymes played a foundational role in evolving biological complexity.
Step-by-step explanation:
The best term for an RNA molecule that possesses catalytic activity is a ribozyme. Ribozymes are ribonucleic acids that catalyze reactions in a manner similar to how enzymes function. These biological catalysts play a crucial role in various cellular processes, such as the processing of newly transcribed RNA, including small nuclear RNA (snRNA) and heteronuclear RNA (hnRNA).
During what is hypothesized to be the RNA World, a stage in the origin of life, RNA molecules not only served as genetic material but also performed catalytic functions essential for life to exist. Ribozymes may have even assisted in primitive enzyme selection, guiding the evolution from RNA-driven catalysis to the modern system of protein enzymes that now dominate biological processes. Some ribozymes also hold the potential to bind amino acids, which was essential for peptide bond formation and the synthesis of proteins.
In the RNA-first hypothesis, the catalytic properties of ribozymes are seen as a foundational mechanism that might have led to the transition from the RNA world to the DNA-RNA-protein world of modern biology. Notably, question 13 provides the answer option of 'C. rRNA' as an RNA type known for its catalytic abilities, highlighting the importance of rRNA in ribosomes for catalysis.