Practice question · Sort into groups
Sort each molecule by the role the RNA world hypothesis assigns it in modern cells.
Groups: Stores information long-term · Carries out catalysis · Does both in modern cells
- Ribosomal RNA
- Protein enzymes
- Ribozymes generally
- DNA
Hints
- Modern life mostly separates the two roles between two molecules.
- RNA is the exception that still does both.
Show the answer
Stores information long-term: DNA
Carries out catalysis: Protein enzymes
Does both in modern cells: Ribosomal RNA, Ribozymes generally
Why
Modern life divides the labour — DNA stores, protein catalyses — but RNA still does both, which is exactly the relic the hypothesis predicts. The ribosome is the clearest case: an RNA enzyme building every protein you have.
Practise The Origin of Life and the RNA World
The app has 4 more questions on this lesson, and keeps your place in the course. Biology I is free to start.
More questions on The Origin of Life and the RNA World
- Why does the RNA world hypothesis resolve the chicken-and-egg problem of DNA and protein?
- Place these stages of early molecular evolution in the order the RNA world hypothesis proposes.
- A hypothetical genetic code uses 4 bases and codons of length 2. How many distinct codons does it have?
- The Last Universal Common Ancestor (LUCA) marks a genealogical bottleneck rather than the inception of…
- Which observations support the idea that RNA preceded DNA and protein?
- The genetic code is essentially the same in bacteria, plants and animals.