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WorksheetsMolecular Biology
Total questions: 20
Worksheet time: 11mins
Which of the following processes involves the duplication of a cell's DNA, resulting in two identical DNA molecules?
Transcription
Translation
DNA Replication
Cell Division
Which strand is synthesized continuously in the 5' to 3' direction during DNA replication?
Lagging Strand
Okazaki Strand
Template Strand
Leading Strand
Which enzyme is responsible for unwinding the DNA helix during the process of DNA replication?
Ligase
Polymerase
Helicase
Primase
What is the result of UV light absorption by pyrimidine bases in DNA?
Formation of purine dimers
Breakage of the DNA strand
Formation of pyrimidine dimers
Conversion of pyrimidines to purines
Which of the following secondary structures can form within a single strand of RNA due to complementary base pairing?
Double helix
Hairpin-loop structure
Z-DNA
Triple helix
Which type of protein binds to specific DNA sequences and enhances transcription by stimulating the assembly of the basal transcription apparatus?
Transcriptional repressor
Helicase
DNA polymerase
Transcriptional activator
What is the name of the complex that includes RNA polymerase, general transcription factors, and the mediator, and is essential for the initiation of transcription?
Basal transcription apparatus
Ribosome
Replication fork
Enhancer complex
In bacterial cells, what sequence near the 5′ end of mRNA allows ribosomes to attach and initiate translation while transcription is still occurring?
Shine-Dalgarno sequence
Promoter sequence
TATA Box
Kozak sequence
What is the full form of CPSF, a key protein involved in the cleavage and polyadenylation of pre-mRNA?
Cytoplasmic Polyadenylation Stimulating Factor
Cleavage and Polyadenylation Specificity Factor
Chromatin Packaging and Signal Factor
Cytosine Phosphorylation Synthase Factor
A molecule that transports amino acids to the ribosome and interacts with codons in mRNA, placing amino acids in their proper order in protein synthesis is:
mRNA
miRNA
SiRNA
tRNA
Which of the following best describes a codon?
A sequence of amino acids that determines a protein's structure.
A group of nucleotides in DNA that specifies a single amino acid in a protein.
A segment of RNA that carries the genetic code from the nucleus to the ribosome.
A sequence of proteins that acts as a signal for cellular transport.
What term describes the phenomenon where more than one codon can specify the same amino acid?
Genetic variation
Degeneracy of the code
Amino acid diversity
What is the process called in which tRNAs bind to their respective amino acids?
tRNA synthesis
Codon recognition
tRNA charging
Amino acid activation
What enzymes are responsible for ensuring the specificity between an amino acid and its tRNA?
Ribozymes
DNA polymerases
Aminoacyl-tRNA synthetases
RNA helicases
What term describes a group of bacterial structural genes that are transcribed together, along with their promoter and additional sequences that control transcription?
Operon
Gene cluster
Transcription unit
Expression system
What term describes operons in which transcription is normally active and must be turned off by a repressor mechanism?
Inducible operons
Repressible operons
Constitutive operons
Transcriptional operons
Which protein is responsible for the active transport of lactose into E. coli cells?
Lactase
Repressor
Permease
β-galactosidase
Which operon in E. coli, responsible for the biosynthesis of the amino acid tryptophan, is an example of a negative repressible operon?
Lac operon
Ara operon
Tryptophan (trp) operon
His operon
What term describes DNA sequences that block or insulate the effect of enhancers in a position-dependent manner?
Insulator
Silencer
Promoter
Operator
What term describes the epigenetic phenomenon where a heritable change affects gene expression without altering the DNA sequence?
Gene activation
DNA methylation
Histone modification
Gene silencing
