What is the full form of DNA?
- Deoxyribonucleic Acid ✔️
- Deoxyribonucleic Alkaline
- Deoxyribose Acid
- Dioxyribonucleic Acid
Which of the following are the four nucleotide bases in DNA?
- Adenine, Thymine, Guanine, Cytosine ✔️
- Adenine, Uracil, Guanine, Cytosine
- Adenine, Thymine, Guanine, Uracil
- Uracil, Thymine, Guanine, Cytosine
What type of bond holds the two strands of DNA together?
- Hydrogen bonds ✔️
- Covalent bonds
- Ionic bonds
- Peptide bonds
In DNA, adenine pairs with which base?
- Thymine ✔️
- Cytosine
- Guanine
- Uracil
What shape is the DNA molecule?
- Double helix ✔️
- Single helix
- Beta sheet
- Alpha helix
What is the backbone of the DNA structure made of?
- Sugar and phosphate ✔️
- Sugar and base
- Phosphate and base
- Protein and phosphate
Which enzyme is responsible for adding nucleotides to a growing DNA strand during DNA replication?
- DNA polymerase ✔️
- RNA polymerase
- Helicase
- Ligase
During DNA replication, which enzyme unwinds the DNA helix?
- Helicase ✔️
- Ligase
- Primase
- Topoisomerase
Which base is not found in DNA?
- Uracil ✔️
- Thymine
- Adenine
- Cytosine
Where is DNA primarily located in a eukaryotic cell?
- Nucleus ✔️
- Cytoplasm
- Ribosome
- Endoplasmic reticulum
DNA Replication
DNA replication is described as:
- Semiconservative ✔️
- Conservative
- Dispersive
- Liberal
What is the function of DNA ligase during DNA replication?
- Joining Okazaki fragments ✔️
- Unwinding the DNA helix
- Adding nucleotides to the new strand
- Synthesizing RNA primers
What is the purpose of a primer in DNA replication?
- To provide a starting point for DNA synthesis ✔️
- To unwind the DNA helix
- To join Okazaki fragments
- To replicate the entire strand
Which direction does DNA polymerase synthesize the new strand?
- 5' to 3' ✔️
- 3' to 5'
- Both 5' to 3' and 3' to 5'
- Neither direction
Which enzyme synthesizes RNA primers during DNA replication?
- Primase ✔️
- Helicase
- Ligase
- DNA polymerase
What are Okazaki fragments?
- Short DNA fragments on the lagging strand ✔️
- RNA fragments used as primers
- Sections of DNA on the leading strand
- Proteins that bind to DNA
Which enzyme removes the RNA primers and fills in the gaps with DNA?
- DNA polymerase I ✔️
- DNA polymerase III
- Helicase
- Ligase
What is the role of topoisomerase during DNA replication?
- Preventing supercoiling ✔️
- Unwinding the DNA helix
- Synthesizing RNA primers
- Sealing gaps between Okazaki fragments
In eukaryotic cells, replication occurs in which part of the cell cycle?
- S phase ✔️
- G1 phase
- G2 phase
- M phase
Which strand is synthesized continuously during DNA replication?
- Leading strand ✔️
- Lagging strand
- Both strands
- Neither strand
Transcription and Translation
Which enzyme is responsible for transcribing DNA into RNA?
- RNA polymerase ✔️
- DNA polymerase
- Ligase
- Helicase
In transcription, which base pairs with adenine in the RNA molecule?
- Uracil ✔️
- Thymine
- Cytosine
- Guanine
The process of copying a gene's DNA sequence into an RNA sequence is called:
- Transcription ✔️
- Translation
- Replication
- Mutation
What is the initial RNA molecule synthesized from DNA called?
- Pre-mRNA ✔️
- mRNA
- tRNA
- rRNA
Which regions of the DNA are transcribed into RNA?
- Exons and introns ✔️
- Only exons
- Only introns
- Neither exons nor introns
What process removes introns from pre-mRNA?
- RNA splicing ✔️
- RNA editing
- RNA processing
- RNA transcription
Where does translation occur in the cell?
- Ribosome ✔️
- Nucleus
- Endoplasmic reticulum
- Golgi apparatus
The three-nucleotide sequence on mRNA that specifies an amino acid is called:
- Codon ✔️
- Anticodon
- Triplet
- Intron
Which type of RNA carries amino acids to the ribosome?
- tRNA ✔️
- mRNA
- rRNA
- snRNA
What is the start codon for translation?
- AUG ✔️
- UAA
- UGA
- UAG
DNA Mutations and Repair
A change in the DNA sequence is known as a:
- Mutation ✔️
- Translocation
- Recombination
- Translation
Which type of mutation involves a single nucleotide change?
- Point mutation ✔️
- Frameshift mutation
- Insertion
- Deletion
A mutation that does not change the amino acid sequence of a protein is called:
- Silent mutation ✔️
- Missense mutation
- Nonsense mutation
- Frameshift mutation
A mutation that results in a premature stop codon is known as a:
- Nonsense mutation ✔️
- Silent mutation
- Missense mutation
- Frameshift mutation
What is a frameshift mutation?
- Addition or deletion of a nucleotide causing a shift in the reading frame ✔️
- Single nucleotide change
- Change in one amino acid
- Change in the promoter region
Which enzyme is involved in proofreading and correcting errors during DNA replication?
- DNA polymerase ✔️
- Helicase
- Ligase
- RNA polymerase
What is the main function of the nucleotide excision repair mechanism?
- Repairing bulky DNA lesions ✔️
- Fixing single nucleotide changes
- Joining Okazaki fragments
- Synthesizing RNA primers
Which type of repair corrects mismatched nucleotides?
- Mismatch repair ✔️
- Base excision repair
- Nucleotide excision repair
- Homologous recombination
What causes thymine dimers in DNA?
- UV radiation ✔️
- X-rays
- Chemical mutagens
- Ionizing radiation
Which repair mechanism is used to repair double-strand breaks in DNA?
- Homologous recombination ✔️
- Mismatch repair
- Base excision repair
- Nucleotide excision repair
Genetic Code and Expression
The genetic code is:
- Universal ✔️
- Unique to each organism
- Only for eukaryotes
- Only for prokaryotes
How many codons are there in the genetic code?
- 64 ✔️
- 20
- 32
- 128
What is the function of a promoter in DNA?
- Initiates transcription ✔️
- Terminates transcription
- Splices RNA
- Translates RNA
Which protein binds to the promoter to initiate transcription?
- RNA polymerase ✔️
- DNA polymerase
- Helicase
- Ligase
What is an operon?
- A group of genes regulated together ✔️
- A single gene
- A type of mutation
- A type of promoter
The lac operon is an example of:
- Inducible operon ✔️
- Repressible operon
- Constitutive operon
- Enhancer operon
Which molecule acts as an inducer for the lac operon?
- Allolactose ✔️
- Lactose
- Glucose
- Galactose
Which type of gene expression regulation occurs at the level of transcription?
- Transcriptional control ✔️
- Post-transcriptional control
- Translational control
- Post-translational control
What are enhancers in DNA?
- DNA sequences that increase transcription ✔️
- DNA sequences that decrease transcription
- Proteins that bind to DNA
- Enzymes that replicate DNA
What is the function of a repressor protein?
- Binds to operator to block transcription ✔️
- Enhances transcription
- Splices RNA
- Synthesizes RNA
DNA Technology
Which technique is used to amplify DNA sequences?
- Polymerase Chain Reaction (PCR) ✔️
- Gel electrophoresis
- DNA sequencing
- Southern blotting
What is the purpose of gel electrophoresis?
- To separate DNA fragments by size ✔️
- To amplify DNA
- To clone DNA
- To sequence DNA
Which enzyme is used in PCR to synthesize new DNA strands?
- Taq polymerase ✔️
- DNA polymerase I
- RNA polymerase
- Ligase
What is the function of restriction enzymes?
- Cutting DNA at specific sequences ✔️
- Amplifying DNA
- Sequencing DNA
- Repairing DNA
Which method is used to determine the sequence of nucleotides in DNA?
- DNA sequencing ✔️
- PCR
- Gel electrophoresis
- Southern blotting
What is the role of a DNA probe in hybridization techniques?
- To bind to complementary DNA sequences ✔️
- To amplify DNA
- To cut DNA
- To repair DNA
Which technology allows for editing of the genome?
- CRISPR-Cas9 ✔️
- PCR
- Gel electrophoresis
- DNA sequencing
Which process involves the insertion of foreign DNA into a cell?
- Transformation ✔️
- Transcription
- Translation
- Replication
What is the purpose of a plasmid in genetic engineering?
- To serve as a vector for DNA insertion ✔️
- To amplify DNA
- To sequence DNA
- To repair DNA
Which technique is used to separate and analyze DNA fragments based on size?
- Gel electrophoresis ✔️
- PCR
- DNA sequencing
- Southern blotting
DNA in Forensics and Medicine
What is DNA fingerprinting used for?
- Identifying individuals ✔️
- Sequencing DNA
- Amplifying DNA
- Repairing DNA
Which type of DNA is often used in forensic analysis due to its variability among individuals?
- Short Tandem Repeats (STRs) ✔️
- Coding sequences
- Introns
- Promoter regions
What is the main purpose of gene therapy?
- To treat genetic disorders by correcting defective genes ✔️
- To sequence DNA
- To amplify DNA
- To analyze DNA fragments
Which type of vector is commonly used in gene therapy?
- Viral vectors ✔️
- Plasmids
- Restriction enzymes
- DNA probes
What is the Human Genome Project?
- An initiative to map the entire human genome ✔️
- A project to amplify DNA
- A project to sequence a single gene
- A project to repair defective genes
Which technique is used to compare DNA samples from different sources?
- DNA profiling ✔️
- PCR
- DNA sequencing
- Southern blotting
What is personalized medicine?
- Tailoring medical treatment to an individual's genetic makeup ✔️
- General medical treatment for all patients
- Standardized treatment based on age
- Standardized treatment based on weight
Which technology is used to detect specific genetic mutations?
- DNA microarrays ✔️
- PCR
- Gel electrophoresis
- Southern blotting
Which medical technique uses CRISPR-Cas9?
- Genome editing ✔️
- DNA amplification
- DNA sequencing
- DNA profiling
What is a genetic marker?
- A specific DNA sequence used for identifying individuals or traits ✔️
- A gene that causes a disease
- An enzyme that cuts DNA
- A protein that repairs DNA
DNA in Evolution and Population Genetics
What is the significance of mitochondrial DNA in evolutionary studies?
- It is inherited maternally and can trace lineage ✔️
- It is inherited paternally and can trace lineage
- It recombines during meiosis
- It is identical in all individuals
Which process increases genetic variation in a population?
- Mutation ✔️
- Genetic drift
- Natural selection
- Gene flow
What is a population bottleneck?
- A sharp reduction in population size leading to loss of genetic diversity ✔️
- Gradual increase in population size
- Movement of individuals between populations
- Introduction of new alleles into a population
Which type of selection favors individuals with average traits?
- Stabilizing selection ✔️
- Directional selection
- Disruptive selection
- Balancing selection
What is gene flow?
- Movement of alleles between populations ✔️
- Random changes in allele frequencies
- Differential survival and reproduction
- Formation of new species
What is genetic drift?
- Random changes in allele frequencies ✔️
- Movement of alleles between populations
- Formation of new species
- Differential survival and reproduction
Which type of selection favors individuals at both extremes of a trait?
- Disruptive selection ✔️
- Stabilizing selection
- Directional selection
- Balancing selection
What is the founder effect?
- Reduced genetic diversity when a new population is established ✔️
- Increased genetic diversity in a large population
- Movement of alleles between populations
- Differential survival and reproduction
Which process can result in new alleles in a population?
- Mutation ✔️
- Genetic drift
- Natural selection
- Gene flow
Which term describes the overall genetic makeup of a population?
- Gene pool ✔️
- Genome
- Chromosome
- Genotype
Advanced Topics in DNA
What is epigenetics?
- Study of changes in gene expression without altering the DNA sequence ✔️
- Study of changes in DNA sequence
- Study of protein synthesis
- Study of DNA replication
What are histones?
- Proteins that help package DNA ✔️
- Enzymes that synthesize DNA
- Enzymes that repair DNA
- RNA molecules that regulate gene expression
What is a telomere?
- The end region of a chromosome ✔️
- The central region of a chromosome
- A gene involved in DNA repair
- An enzyme that synthesizes DNA
Which enzyme maintains the length of telomeres?
- Telomerase ✔️
- DNA polymerase
- RNA polymerase
- Ligase
What is chromatin?
- Complex of DNA and protein in the nucleus ✔️
- Pure DNA molecule
- Pure RNA molecule
- Protein complex that synthesizes DNA
What is the function of microRNA (miRNA)?
- To regulate gene expression by degrading mRNA ✔️
- To synthesize DNA
- To splice RNA
- To transcribe DNA
What is a single nucleotide polymorphism (SNP)?
- A variation in a single nucleotide ✔️
- A variation in a whole gene
- A type of mutation that deletes a gene
- A type of chromosomal rearrangement
What is an enhancer?
- A DNA sequence that increases transcription of a gene ✔️
- A protein that represses transcription
- An RNA molecule that synthesizes protein
- An enzyme that repairs DNA
What is a transcription factor?
- A protein that regulates gene expression by binding to DNA ✔️
- An enzyme that synthesizes RNA
- An RNA molecule that splices introns
- A protein that unwinds DNA
What is the function of the TATA box in a promoter?
- To help position RNA polymerase ✔️
- To terminate transcription
- To enhance translation
- To splice RNA
Miscellaneous
What is the role of ribosomal RNA (rRNA) in the cell?
- To form the core of the ribosome and catalyze protein synthesis ✔️
- To carry amino acids to the ribosome
- To serve as a template for protein synthesis
- To regulate gene expression
What is the central dogma of molecular biology?
- DNA -> RNA -> Protein ✔️
- RNA -> DNA -> Protein
- Protein -> RNA -> DNA
- DNA -> Protein -> RNA
What is a codon?
- A three-nucleotide sequence that codes for an amino acid ✔️
- A single nucleotide
- A protein that binds to DNA
- A sequence of DNA that regulates transcription
What is the function of transfer RNA (tRNA)?
- To bring amino acids to the ribosome ✔️
- To synthesize DNA
- To transcribe DNA
- To degrade mRNA
What is a genetic code?
- A set of rules by which information encoded in genetic material is translated into proteins ✔️
- A set of enzymes that synthesize DNA
- A set of proteins that bind to DNA
- A set of RNA molecules that splice introns
Which molecule is a key component of the spliceosome?
- snRNA ✔️
- tRNA
- mRNA
- rRNA
What is alternative splicing?
- Process by which different mRNAs are produced from the same pre-mRNA ✔️
- Synthesis of RNA from DNA
- Degradation of RNA
- Translation of RNA into protein
What is a gene?
- A segment of DNA that codes for a protein or RNA molecule ✔️
- A protein that synthesizes DNA
- A ribosome that synthesizes protein
- A lipid that regulates gene expression
What is the role of a ribosome in the cell?
- To synthesize proteins ✔️
- To transcribe DNA
- To replicate DNA
- To repair DNA
What is a karyotype? -
· A display of an individual's complete set of chromosomes ✔
· A sequence of DNA
· A type of RNA
· A type of protein
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