Prepare for NEET Biology Molecular Basis of Inheritance with MCQs & PYQs on NEET.GUIDE. Access free practice, previous year questions, and expert explanations of DNA replication and genetics.
The Human Genome Project revealed that the human genome contains approximately what percentage of coding sequences?
50%
25%
10%
Less than 2%
Which sequencing method was NOT a major contributor to the initial completion of the Human Genome Project?
Sanger sequencing
Automated DNA sequencing
Next-generation sequencing (NGS)
BAC-based sequencing
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 of the following is NOT a component of a DNA nucleotide?
Deoxyribose sugar
Phosphate group
Nitrogenous base
Ribose sugar
The two strands of a DNA molecule are held together by:
Covalent bonds
Ionic bonds
Hydrogen bonds
Peptide bonds
