Biology
Molecular Genetics
917 Questions
Molecular genetics explores the mechanisms of genetic information transfer, including DNA replication, transcription, and translation. It is a core component of biology syllabi. These concepts frequently appear in general science sections of major competitive exams.
DNA replicationTranscription processTranslation processRNA typesCentral dogma
Molecular Genetics Questions
What is the process by which genetic information encoded in DNA is copied into a complementary RNA molecule?
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Transcription
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Translation
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Replication
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Mutation
A
Correct answer
Explanation
Transcription is the process by which an enzyme called RNA polymerase synthesizes a complementary RNA molecule using one strand of DNA as a template.
Which enzyme is responsible for catalyzing the transcription of DNA into RNA?
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RNA polymerase
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DNA polymerase
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Helicase
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Ligase
A
Correct answer
Explanation
RNA polymerase is the enzyme that catalyzes the transcription of DNA into RNA. It unwinds the DNA double helix, synthesizes a complementary RNA strand, and then rewinds the DNA.
What is the name of the RNA molecule that is synthesized during transcription and serves as a template for protein synthesis?
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Messenger RNA (mRNA)
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Transfer RNA (tRNA)
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Ribosomal RNA (rRNA)
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Small nuclear RNA (snRNA)
A
Correct answer
Explanation
Messenger RNA (mRNA) is the RNA molecule that is synthesized during transcription and serves as a template for protein synthesis. It carries the genetic information from DNA to the ribosomes, where it is translated into a protein.
What is the process by which the genetic information encoded in mRNA is converted into a protein?
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Transcription
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Translation
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Replication
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Mutation
B
Correct answer
Explanation
Translation is the process by which the genetic information encoded in mRNA is converted into a protein. It occurs in the ribosomes, where tRNA molecules bring amino acids to the ribosome in the correct order specified by the mRNA sequence.
What is the name of the molecule that carries amino acids to the ribosome during translation?
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Messenger RNA (mRNA)
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Transfer RNA (tRNA)
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Ribosomal RNA (rRNA)
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Small nuclear RNA (snRNA)
B
Correct answer
Explanation
Transfer RNA (tRNA) is the molecule that carries amino acids to the ribosome during translation. Each tRNA molecule is specific for a particular amino acid and recognizes the corresponding codon on the mRNA.
What is the sequence of three nucleotides on mRNA that codes for a specific amino acid?
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Codon
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Anticodon
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Intron
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Exon
A
Correct answer
Explanation
A codon is a sequence of three nucleotides on mRNA that codes for a specific amino acid. Each codon corresponds to a particular amino acid or a stop signal.
What is the process by which certain regions of a pre-mRNA molecule are removed and the remaining regions are joined together to form a mature mRNA molecule?
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Splicing
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Transcription
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Translation
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Replication
A
Correct answer
Explanation
Splicing is the process by which certain regions of a pre-mRNA molecule are removed and the remaining regions are joined together to form a mature mRNA molecule. This process removes introns (non-coding regions) and retains exons (coding regions).
What is the name of the enzyme that catalyzes the splicing of pre-mRNA?
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Spliceosome
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RNA polymerase
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Helicase
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Ligase
A
Correct answer
Explanation
The spliceosome is the enzyme that catalyzes the splicing of pre-mRNA. It is a complex of small nuclear ribonucleoproteins (snRNPs) that recognizes and removes introns from the pre-mRNA.
What is the process by which gene expression is regulated to ensure that the right genes are expressed at the right time and in the right amount?
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Gene Regulation
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Transcription
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Translation
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Replication
A
Correct answer
Explanation
Gene regulation is the process by which gene expression is regulated to ensure that the right genes are expressed at the right time and in the right amount. This process involves various mechanisms, such as transcriptional regulation, translational regulation, and epigenetic modifications.
What is the name of the region of DNA that controls the transcription of a gene?
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Promoter
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Enhancer
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Intron
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Exon
A
Correct answer
Explanation
The promoter is the region of DNA that controls the transcription of a gene. It is located upstream of the transcription start site and contains specific sequences that are recognized by RNA polymerase and other transcription factors.
What is the name of the protein that binds to the promoter and initiates transcription?
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RNA polymerase
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Transcription factor
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Helicase
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Ligase
B
Correct answer
Explanation
Transcription factors are proteins that bind to the promoter and initiate transcription. They recognize specific DNA sequences and help RNA polymerase to bind to the promoter and start transcription.
What is the name of the process by which the expression of a gene is turned off?
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Gene Silencing
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Transcription
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Translation
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Replication
A
Correct answer
Explanation
Gene silencing is the process by which the expression of a gene is turned off. This can occur through various mechanisms, such as DNA methylation, histone modification, and RNA interference.
What is the name of the small RNA molecule that plays a role in gene silencing by targeting and degrading specific mRNA molecules?
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MicroRNA (miRNA)
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Transfer RNA (tRNA)
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Ribosomal RNA (rRNA)
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Small nuclear RNA (snRNA)
A
Correct answer
Explanation
MicroRNA (miRNA) is a small RNA molecule that plays a role in gene silencing by targeting and degrading specific mRNA molecules. It binds to the 3' untranslated region (UTR) of mRNA and prevents translation or causes the mRNA to be degraded.
Which of the following is a type of cancer genomics?
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Whole-genome sequencing
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Exome sequencing
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RNA sequencing
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All of the above
D
Correct answer
Explanation
Cancer genomics is the study of the genome of cancer cells. There are a number of different types of cancer genomics, including whole-genome sequencing, exome sequencing, and RNA sequencing.
What is the process by which DNA makes a copy of itself?
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Replication
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Transcription
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Translation
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Mutation
A
Correct answer
Explanation
Replication is the process by which DNA makes an identical copy of itself. It occurs during cell division and ensures that each new cell receives a complete set of genetic information.