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NEET Questions / Botany / Molecular Basis of Inheritance / Rna World
The RNA world hypothesis posits RNA as the primary genetic material before DNA. Which of the following properties of RNA is LEAST supportive of this hypothesis?
RNA's ability to catalyze reactions (ribozymes)
RNA's ability to store genetic information
RNA's susceptibility to alkaline hydrolysis
The presence of RNA in key cellular processes like translation
If the RNA world hypothesis is correct, which of the following would be the MOST likely scenario for the emergence of DNA?
DNA spontaneously arose independent of RNA and eventually outcompeted RNA.
Proteins evolved first and then catalyzed the formation of DNA from RNA.
RNA developed the ability to synthesize deoxyribonucleotides and polymerize them, eventually leading to DNA genomes.
Extraterrestrial DNA was introduced to Earth and replaced RNA.
A critical piece of evidence supporting the RNA world hypothesis is the existence of ribozymes. Which characteristic of ribozymes is MOST significant in this context?
Their sensitivity to RNase degradation
Their single-stranded structure
Their ability to catalyze both self-replication and peptide bond formation
Their presence in both prokaryotes and eukaryotes
Which prebiotic condition would have MOST significantly hindered the formation of stable RNA polymers in the early Earth environment?
An abundance of organic molecules like amino acids and nucleotides
The presence of clay minerals that can catalyze RNA polymerization
High concentrations of metal ions that catalyze RNA hydrolysis
Alternating cycles of wetting and drying
The “RNA world” hypothesis proposes that RNA preceded DNA and proteins as the primary genetic material. A major challenge to this hypothesis is the relative instability of RNA compared to DNA. Why is RNA less stable?
RNA utilizes uracil instead of thymine.
RNA is typically single-stranded.
The 2'-OH group on the ribose sugar makes RNA susceptible to hydrolysis.
RNA is shorter than DNA.
In the context of the RNA world hypothesis, the discovery of catalytic RNA molecules (ribozymes) was crucial. Which of the following functions performed by ribozymes is MOST relevant to supporting the hypothesis?
Degrading proteins, demonstrating early enzymatic activity
Catalyzing RNA polymerization, suggesting a mechanism for self-replication
Splicing RNA, indicating a role in gene regulation
Synthesizing amino acids, demonstrating prebiotic metabolic pathways
Which molecule is hypothesized to have been the primary genetic material in the RNA world?
DNA
RNA
Proteins
Lipids
What crucial role does RNA play in the RNA world hypothesis?
Only genetic information storage
Only catalysis
Both genetic information storage and catalysis
Structural support
What are RNA molecules with catalytic activity called?
Enzymes
Ribozymes
Ribosomes
Deoxyribozymes
Which of these is NOT a supporting argument for the RNA world hypothesis?
RNA's ability to self-replicate
RNA's catalytic properties
The existence of ribozymes
DNA's higher stability
