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
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RNA is the genetic material of bacteria
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RNA is the genetic material of all viruses
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DNA is the genetic material of all organisms
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Some viruses have RNA as genetic material
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D
Correct answer
Explanation
Correct Answer: Some viruses have RNA as genetic material
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chromosomes
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DNA
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proteins
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vitamins
C
Correct answer
Explanation
Genes express their trait by getting converted into proteins.
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DNA polymerase
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Histones
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Nucleolar DNA
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Tubulin protein
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A
Correct answer
Explanation
The G1 phase, or Gap 1 phase, is the first of four phases of the cell cycle that take place in eukaryotic cell division. In this part of interphase, the cell synthesises mRNA and proteins in preparation for subsequent steps that lead to mitosis. DNA polymerase is a protein. This is synthesised in the G1 phase.
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transcription
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translation
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replication
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transduction
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C
Correct answer
Explanation
DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule.
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Exons
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Introns
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Both 1 and 2
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None of these
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A
Correct answer
Explanation
These are the coding sequences which code for a protein or RNA.
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Transduction
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Translation
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DNA amplification
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None of the above
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C
Correct answer
Explanation
It is a method of making multiple copies of a DNA sequence, involving repeated reactions with a polymerase.
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transduction
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DNA amplification
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translation
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None of these
B
Correct answer
Explanation
The polymerase chain reaction (PCR) is a technique that is used in molecular biology to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence.
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ribosomes
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mRNA
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tRNA
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DNA
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A
Correct answer
Explanation
The nucleolus makes ribosomal subunits from proteins and ribosomal RNA, also known as rRNA.
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binding of repressor on silencer regions
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transport of messenger RNA into the cytoplasm
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decreasing messenger RNA stability in the cytoplasm
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Both (b) and (c)
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A transcription factor acts on the DNA
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The signal molecule binds to RNA
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A new protein is made in the target cell
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The signal molecule binds to a receptor.
D
Correct answer
Explanation
The first effect of any signal molecule must involve the binding of the molecule to a receptor.
C
Correct answer
Explanation
A DNA triplet of CGT would yield an mRNA codon of GCA. The complementary tRNA anticodon would therefore be CGU.
C
Correct answer
Explanation
A functional strand of mRNA must have a start and a stop codon. The start codon often also codes for the amino acid methionine, which may or may not end up being a part of the final protein. However, the stop codon would not code for an amino acid. Thus, with 66 codons in the mRNA, there could be as many as 65 amino cells in the protein product.
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DNA polymerase can only add to an existing strand of nucleotides
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DNA polymerase can only add to an existing DNA strand
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DNA primase is the first enzyme in the replication complex.
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All of the above
A
Correct answer
Explanation
DNA polymerase cannot initiate the building of a nucleotide strand; it can only add to an existing strand. Thus, RNA primers are necessary to begin DNA synthesis.
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Cycloheximide blocks elongation during translation.
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Formylated tRNA is necessary for initiation of translation.
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A single mRNA specifies for more than one gene product.
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Erythromycin inhibits elongation during translation.
A
Correct answer
Explanation
In eukaryotic cells, cycloheximide blocks elongation during translation.
B
Correct answer
Explanation
The three codons involved in the termination of translation are UGA, UAG, and UAA. They are called stop or nonsense codons. A stop codon is a nucleotide triplet within messenger RNA that signals a termination of translation. They are a normal part of the protein synthesis.