#1
Which molecule is considered as the 'building block' of nucleic acids?
Nucleotide
ExplanationBasic unit composing DNA and RNA.
#2
Which of the following bases is not found in RNA?
Thymine
ExplanationFound in DNA, not RNA.
#3
Which of the following represents the central dogma of molecular biology?
DNA → RNA → Protein
ExplanationFlow of genetic information.
#4
Which of the following is not a type of RNA involved in gene expression?
Deoxyribosomal RNA (drRNA)
ExplanationNon-existent RNA type.
#5
Which of the following is a post-transcriptional modification of mRNA?
Polyadenylation
ExplanationAdds poly(A) tail to mRNA.
#6
Which enzyme is responsible for adding nucleotides to the growing RNA chain during transcription?
RNA polymerase
ExplanationCatalyzes RNA synthesis.
#7
What is the function of DNA polymerase during DNA replication?
Adds nucleotides to the growing DNA strand
ExplanationEnzyme responsible for DNA synthesis.
#8
In eukaryotic cells, where does transcription occur?
Nucleus
ExplanationTranscription site in eukaryotes.
#9
What is the primary function of messenger RNA (mRNA) in the process of protein synthesis?
Serves as a template for protein synthesis
ExplanationCarries genetic information from DNA to ribosomes.
#10
Which enzyme is responsible for unwinding the DNA double helix during transcription?
RNA polymerase
ExplanationEnzyme initiating transcription.
#11
What is the function of a promoter sequence in gene expression?
Regulates the rate of transcription initiation
ExplanationInitiates transcription.
#12
Which of the following is an example of a silent mutation?
Substitution of a nucleotide with no change in amino acid sequence
ExplanationMutation with no phenotypic effect.
#13
Which of the following is a function of transfer RNA (tRNA)?
Transfers amino acids to the ribosome
ExplanationBrings amino acids to ribosomes.
#14
What is the role of ribosomal RNA (rRNA) in translation?
Forms the structural and functional components of ribosomes
ExplanationConstituent of ribosomes.
#15
What is the role of the Shine-Dalgarno sequence in prokaryotic translation?
Facilitates ribosomal binding to mRNA
ExplanationInitiates translation in prokaryotes.
#16
What is the function of the polyadenylation signal sequence in eukaryotic mRNA processing?
Adds a poly(A) tail to the mRNA
ExplanationStabilizes mRNA and promotes translation.
#17
What is the significance of alternative splicing in eukaryotic gene expression?
It allows for the production of multiple protein isoforms from a single gene
ExplanationIncreases proteomic diversity.
#18
What is the function of the spliceosome?
Facilitates mRNA splicing
ExplanationRemoves introns from pre-mRNA.