AP Bio Study Guide

Big Idea 1.D

What is the RNA World hypothesis?

The RNA world concept hypothesizes that about four billion years ago, the first genetic substance on Earth was the small, single-stranded RNA molecule.

Ribozyme, a type of RNA, can carry out many functions:

  • Catalyze reactions (like enzymes do)
  • Splices RNA by itself, without the need for proteins
  • Removes its own introns during RNA processing
  • Joins amino acids together to form a polypeptide during translation in ribosomes