Refer to the figure below.Part A shows the structure of one of the RNA molecules in a ribosome.Part B shows how the progress of protein synthesis is affected when one of the hydroxyl groups in an adenine nucleotide (adenine 2451 in part A) in this RNA molecule is chemically altered. A ribosome functions as the site of protein synthesis in modern cells.Structurally, a ribosome is composed of several protein and RNA molecules that combine in a complex.Based on the information shown, which statement accurately provides evidence for the "RNA world" hypothesis of the origin of life on Earth?
A) Modern ribosomes are large multimolecular complexes.
B) Protein synthesis in modern ribosomes is catalyzed by an RNA molecule, not by a protein.
C) Some chemical modifications of a ribosomal RNA molecule do not change its biological activity.
D) Ribosomal RNA uses intrachain base pairing to stabilize its three-dimensional structure.
E) Ribosomal RNA is single-stranded.

Question

Refer to the figure below.Part A shows the structure of one of the RNA molecules in a ribosome.Part B shows how the progress of protein synthesis is affected when one of the hydroxyl groups in an adenine nucleotide (adenine 2451 in part A) in this RNA molecule is chemically altered.  A ribosome functions as the site of protein synthesis in modern cells.Structurally, a ribosome is composed of several protein and RNA molecules that combine in a complex.Based on the information shown, which statement accurately provides evidence for the "RNA world" hypothesis of the origin of life on Earth?
A) Modern ribosomes are large multimolecular complexes. 
B) Protein synthesis in modern ribosomes is catalyzed by an RNA molecule, not by a protein. 
C) Some chemical modifications of a ribosomal RNA molecule do not change its biological activity. 
D) Ribosomal RNA uses intrachain base pairing to stabilize its three-dimensional structure. 
E) Ribosomal RNA is single-stranded.

Quizplus · Accepted Answer

Part B shows that the chemical alteration of an adenine nucleotide in the RNA molecule affects protein synthesis, indicating that RNA plays a critical role in protein synthesis. This supports the RNA world hypothesis, which proposes that RNA was the first self-replicating molecule and served as both genetic material and enzyme-like catalysts in the absence of proteins.

Refer to the Figure Below