AP BIOLOGY

Detailed explanation-1: -The RNA world hypothesis suggests that life on Earth began with a simple RNA molecule that could copy itself. The RNA world hypothesis suggests that life on Earth began with a simple RNA molecule that could copy itself without help from other molecules. DNA, RNA, and proteins are central to life on Earth.

Detailed explanation-2: -In an RNA world, the standard theory says, life could have existed as complex proto-RNA strands that were able to both copy themselves and compete with other strands. Later, these ‘RNA enzymes’ could have evolved the ability to build proteins and ultimately to transfer their genetic information into more-stable DNA.

Detailed explanation-3: -The general notion of an “RNA World” is that, in the early development of life on the Earth, genetic continuity was assured by the replication of RNA and genetically encoded proteins were not involved as catalysts.

Detailed explanation-4: -Walter Gilbert, a Harvard molecular biologist, was the first to use the term “RNA World” in an article published in 1986. The hypothesis posists that DNA later became the genetic material as a result of evolution because RNA was a relatively unstable molecule.

Detailed explanation-5: -The hypothesis that RNA preceded DNA and proteins in evolution. In the earliest cells, pre-RNA molecules would have had combined genetic, structural, and catalytic functions and these functions would have gradually been replaced by RNA.