DNA Biology Practice Test

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• Which description applies to the DNA backbone?
• What base pairing rules and bonds stabilize the DNA double helix?
• Information in DNA and RNA is stored in the sequence of the nitrogenous bases. Information is contained in which component?
• Where is the outgoing tRNA recycled to pick up another amino acid to take to the ribosome?
• Proteins that assist the binding of RNA polymerase to a promoter are called _____________.
• True/False: The lac repressor is active in the absence of lactose.
• Which statement best describes the overall DNA structure described?
• In eukaryotes, chromatin condensation is a mechanism to regulate gene expression.
• When lactose is present, which molecule binds to the repressor to inactivate it?
• During which process does tRNA move to the P site, the empty tRNA exits from the E site, and the A site codon is ready for the next tRNA?
• DNA is ______ stranded.
• Which statement is true about housekeeping genes in expression studies?
• Which chromosomal aberration is characterized by moving a segment to a nonhomologous chromosome?
• In Hershey-Chase experiments, which radiolabel was used to track DNA?
• Translation is the synthesis of __________.
• Which of the following describes the product of transcription?
• Ribosomal RNA is abbreviated as ______.
• What is the primary difference between a promoter and a transcription factor in regulating transcription?
• In the trp operon, presence of tryptophan results in which effect on transcription?
• What determines how nucleotides are grouped into codons during translation?
• Describe the DNA sugar-phosphate backbone.
• Which blot technique is used to detect RNA transcripts?
• Which statement best describes basal transcription factors?
• Which statement about X chromosome dosage in mammals is true?
• During translation initiation, the first amino acid-tRNA enters the ribosome at which site?
• What information does a plasmid map convey that is essential for cloning experiments?
• In the Hershey-Chase experiments, which component enters the bacterial cell after infection?
• True or False: Polycistronic mRNA is transcribed from the lac operon when lactose is present.
• What are the two main DNA repair pathways after a CRISPR-Cas9 induced break, and how do they differ?
• During RNA splicing, introns are removed from pre-mRNA.
• Which statement describes Chargaff's rule?
• What is the significance of an origin of replication on a plasmid?
• True or false: the introns of eukaryotic mRNA are spliced together.
• Barr bodies are typically found in the nucleus of which cells?
• Basal transcription factors are essential for transcription and cannot increase the rate by themselves.
• The Hershey-Chase experiment concluded that genetic material is composed of DNA because the radiolabel found inside the bacterial cells was associated with:
• Which statement about DNA strand orientation is correct?
• What type of bond holds complementary bases together across the DNA double helix?
• To achieve condensation, DNA wraps around a group of ________ molecules, forming a nucleosome.
• Which processing event occurs to create the primary transcript by adding a 5' cap and a 3' poly-A tail?
• Which statement describes replication fork and leading/lagging strand synthesis?
• Which molecule carries amino acids to the ribosome during translation?
• In the Hershey-Chase experiment, which observation supported the conclusion that genetic material is DNA?
• How does the antiparallel orientation of DNA strands affect replication?
• How does DNA proofreading by DNA polymerase contribute to replication fidelity?
• What is a common synthetic biology approach to create novel DNA sequences with desired properties?
• How are genetic linkage maps constructed in genetics?
• PCR-based genetic tests detect what?
• Which statement about the Xist gene is true?
• The structure that causes the synthesis of RNA to cease is the __________.
• Because each old strand of the parent molecule serves a(n) _________ for and is present in each new daughter strand, the process of DNA replication can be described as __________.
• During transcription, which molecules align with the DNA template to form messenger RNA?
• During translation, mRNA is translated into polypeptides by which molecules?
• Which chromosomal aberration results in the loss of a chromosome segment?
• What does Mendel's Law of Segregation state?
• Which statement correctly describes adenine's pairing and classification?
• DNA is located in the ______ of the cell, while the protein synthesis machinery resides in the ______.
• How do restriction enzymes create cohesive versus blunt ends, and why does this matter for cloning?
• What distinguishes transcription initiation in prokaryotes from eukaryotes?
• The lac operon produces what type of mRNA?
• What is the genotypic ratio from a cross between two heterozygotes for a single gene?
• True or false: X chromosome inactivation equalizes the gene dosage between mammalian males and females.
• Tightly compacted, inactive chromatin is called ________.
• Guanine pairs with which base?
• Exons in mRNA code for the amino acid sequence after processing.
• Which chromosomal aberration can create a fusion gene by joining segments from two different chromosomes?
• True or False: Double-stranded DNA consists of two antiparallel strands, with one running 5' to 3' and the other 3' to 5'.
• Which statement about the central dogma is correct?
• Almost all organisms use this ________, suggesting an early evolutionary origin.
• The final phase of translation is called which of the following?
• In termination, what binds to the stop codon to cleave the polypeptide?
• The nucleotides are joined to each other by an enzyme called DNA __________.
• What is a key role of transposons in genome evolution?
• During mRNA processing, the 5' cap and 3' poly-A tail are added before intron removal.
• Guanine is which kind of base?
• RNA polymerase binds to the __________.
• In a diploid organism, which statement accurately defines an allele?
• Describe the difference between transformation and transfection.
• The trp operon consists of how many genes encoding tryptophan biosynthesis enzymes?
• Is it true that the codon of tRNA is complementary to the anticodon of mRNA?
• How do chromatin structure changes influence transcriptional accessibility?
• A final enzyme, DNA ____________, then seals any breaks in the sugar-phosphate backbone.
• Which sequencing approach sequences millions of DNA fragments in parallel for high throughput?
• Which bases are purines?
• Which base is the complement to cytosine?
• The process of ___________ removes noncoding sections called __________ while leaving the protein-coding portions of the gene called __________.
• Before transcription begins, euchromatin needs to be modified by a chromatin __________.
• Which molecule inactivates the lac repressor by binding to it?
• Describe how epigenetic modifications influence gene expression without changing the DNA sequence.
• Non Coding sequences called ____ are removed from the primary transcript after the cap and tail are added.
• When lactose is absent, transcription does not occur because the ________ binds to the ________ and prevents ________ from binding to the promoter.
• Which chromosomal aberration reverses the orientation of a chromosome segment without removing or duplicating material?
• Which phase lengthens the growing polypeptide chain?
• Which statement accurately describes the Hershey-Chase experiment related to the genetic material?
• In GWAS, how are disease-associated SNPs identified?
• Where does the empty tRNA exit the ribosome during elongation?
• What is the correct order of steps in a PCR cycle?
• RNA splicing occurs in the nucleus of eukaryotic cells.
• Which scientist used X-ray diffraction to reveal the DNA double-helix structure?
• What are the roles of promoter regions and enhancers in transcription regulation?
• True or False: During RNA splicing, small nuclear ribonucleoproteins called SNRNPs help to remove introns.
• RNA contains the sugar ______.
• According to the central dogma, which process is part of genetic information flow?
• Complementary messenger RNA strand from the DNA base sequence CTGAC would be __________.
• The process of ___________ removes exons to create a different protein from the same gene.
• True or false: Hershey-Chase labeled the phage DNA with radioactive 32P?
• How many alleles does a gene typically have in a diploid organism?
• Which transcription factor is required to release RNA polymerase II from promoter-proximal pausing into productive elongation?
• True/False: In the presence of tryptophan, transcription of the trp operon is on.
• Cytosine is which of the following?
• Which of the following statements about RNA splicing is FALSE?
• How many different amino acids are used to build proteins in living organisms?
• Which statement about telomerase activity in human somatic cells is true?
• In the presence of tryptophan, tryptophan binds to the ________.
• Which statement best describes the scope of regulation in eukaryotic gene expression?
• In the Hershey-Chase experiment, which component of the phage was radioactively labeled with 32P?
• True or false: the addition of a phosphate to a protein after it is produced is an example of post-translational modification.
• What are introns?
• In eukaryotes, chromatin ______ is a way to keep genes turned on and off.
• Where does the assembly of transcription factors begin relative to the transcription start site?
• The first phase of translation, called __________, brings together the two ______________, the mRNA and the ______________ complex.
• Which molecular complex is primarily involved in splicing introns from pre-mRNA in eukaryotes?
• How can CRISPR-Cas9 be used for gene editing?
• Which of the following best describes the difference between a silent mutation and a missense mutation with regard to protein function?
• How does the lac operon regulate gene expression in response to lactose?
• How can non-synonymous mutations be evaluated for potential impact on a protein?
• In bacteria, a cluster of functionally related genes that are transcribed together is called an ______.
• Which statement best describes the role of study design controls in gene expression experiments?
• During transcription, DNA is ______ into mRNA, and each set of three nucleotides, also called ______, code for specific ______.
• A nucleotide is composed of which components?
• New ______________ position themselves along the parent strands through ______________ base pairing.
• Which statement accurately describes the result of transcription in human cells?
• Which method specifically assesses DNA fragment sizes and copy number, not just presence of a sequence?
• Chromatin remodeling complexes function primarily to ______.
• In meiosis, how does independent assortment contribute to genetic variation?
• Eukaryotic transcription factors include activators and coactivators.
• Which statement is a regulatory mechanism characteristic of eukaryotic gene regulation?
• Which statement best describes the role of snRNPs in RNA splicing?
• During translation, which statement best describes the role of tRNA anticodons?
• What carries amino acids to the ribosome?
• DNA forms a ______.
• Non coding sequences within eukaryotic genes are called _____.
• In a classic monohybrid cross with complete dominance, what is the typical phenotypic ratio?
• Transcription is carried out by which enzyme?
• What is the sugar component in the DNA backbone?
• PCR relies on which principle and what are the core steps in a cycle?
• True or false: Once a cell undergoes X chromosome inactivation, all of its daughter cells will have the same X chromosome inactivated.
• In ______________, messenger RNA must be processed before it leaves the ______________.
• Alternative splicing increases proteome diversity.
• Under which condition is lacZYA transcription maximal?
• The phage used in the experiment consisted of a DNA molecule surrounded by a protein coat.
• True/False: the trp is found in humans.
• What is promoter-proximal pausing, and what is its significance in metazoan transcription?
• RNA is not a double helix.
• Which repair pathway removes a single damaged base and fills the gap?
• What are exons?
• Which protein binds to the operator to block transcription in the lac operon?
• What does a higher recombination frequency imply about the genetic distance between two genes?
• In the absence of tryptophan, the trp repressor is ______.
• If 35S were found in progeny phages rather than 32P, which component would this indicate enters the host cell?
• What is the result of alternative RNA splicing in eukaryotic gene expression?
• What is a key consequence of nondisjunction during meiosis?
• The segment of DNA where transcription begins is called the promoter region.
• Francois Jacob and Jacques Monod described such a cluster of genes and the DNA sequences that control its transcription as a(n) ______________.
• The segment of DNA where messenger RNA synthesis begins is called the ______.
• When lactose is present, which enzyme binds to the promoter to Initiate transcription?
• How many bases are encompassed in one complete 360-degree turn of the DNA helix?
• In the lac operon, the genes required to digest lactose are transcribed together because they are controlled by which DNA element?
• Which of the following is not part of the lac operon?
• Which statement correctly distinguishes linkage from independent assortment?
• What are SNPs and how can they affect gene function or phenotype?
• Describe the redundancy of the genetic code and identify the start codon.
• Where does transcription occur in the cell?
• The Barr body is an example of tightly compacted inactive chromatin found in mammalian females.
• Which description best captures the structure of DNA components?
• Proteins that bind to enhancers, or regulatory regions of DNA, that speed transcription dramatically, are called ___________.
• Which of the following is an example of aneuploidy?
• Which epigenetic mechanism can be inherited across generations without changing the DNA sequence?
• How does mismatch repair function after DNA replication?
• Which primer design guideline is correct for PCR to avoid non-specific amplification?
• mRNA contains three-base units that code for amino acids. These units are called _____.
• Transcription begins in the _______ when ______ unzips a DNA molecule.
• The most efficient control of eukaryotic gene expression is achieved at the level of __________.
• Compare and contrast PCR and qPCR.
• Which molecule functions as the adaptor that carries amino acids to the ribosome during translation?
• DNA contains the sugar ______.
• In translation, which component catalyzes peptide bond formation?
• In the Hershey-Chase experiment, which molecule was labeled with 32P to track genetic material?
• In DNA, adenine pairs with __________.
• What is recombination frequency and how is it used to map genes?
• What is the typical effect of a frameshift mutation?
• A cell with three X chromosomes will contain ________.
• Alternative splicing primarily contributes to transcript diversity by
• Which team is credited with proposing the double-helix model after weighing evidence?
• The lac repressor binds to what site within the lac operon?
• What is the function of enhancers in transcription regulation?
• Thymine is which of the following in DNA?
• Tryptophan binds to which repressor to regulate the trp operon?
• Which statement correctly describes base excision repair and nucleotide excision repair?
• In the genetic code, how many codons code for amino acids and how many act as stop signals?
• How do Southern blotting and Northern blotting differ?
• In a typical female with two X chromosomes, how many Barr bodies are present?
• Different RNA sequences can be formed from a single mRNA transcript because ______.
• How can gene therapy restore function in a genetic disease? Example.
• MyoD alone can activate genes necessary for ________ to become muscle cells.
• The synthesis of messenger RNA is called transcription.
• True or False: Asymmetrical spacing of the DNA backbones generates major and minor grooves.
• During DNA replication, the two strands separate as the _________ bonds connecting the parent strands are broken by an enzyme called ___________.
• Which cellular processes can regulate gene expression in eukaryotes?
• Which enzyme seals the gaps between Okazaki fragments on the lagging strand?
• Which molecule binds to the operator to prevent transcription when lactose is absent?
• Synthesis of a new RNA strand occurs in which direction?
• What type of bond holds the DNA base pairs together across the two strands?
• During translation, what happens when the ribosome shifts three nucleotides along the mRNA?
• Are introns coding sequences?
• RNA nucleotides align themselves to complementary base pairs on the ________ and form ________.
• In RNA, adenine pairs with __________.
• DNA wraps around a core of histone proteins to form a __________.
• True or false: The various transcription factors bind to the promoter.
• Translation termination occurs when a stop codon is encountered at which ribosomal site?
• During transcription, double-stranded DNA is transcribed into a complementary molecule of ________.
• Which region serves as the binding site for RNA polymerase to initiate transcription in a prokaryote?
• Transfer RNA is abbreviated as ______.
• Epistasis occurs when one gene's allele masks another gene's effect. Which example best illustrates this?
• Which statement best describes qPCR compared with standard PCR?
• Which statement is true about somatic mutations?
• Which molecule carries genetic information in most organisms?
• RNA is typically __________.
• Which repair process targets bulky DNA lesions that distort the helix?
• The 5' end modified with the addition of a(n) _________ and the 3' end is modified with the addition of a(n) ___________ tail, both of which stabilize the mRNA molecule.
• During elongation, which ribosomal site receives the tRNA carrying the growing polypeptide chain?
• Which type of mutation is not heritable and occurs in body cells?
• Unlike prokaryotic cells whose genes are controlled mostly through ________, eukaryotic gene regulation occurs mostly through DNA binding proteins.
• What is the role of telomeres and telomerase in chromosome stability?
• Which part forms the backbone of the DNA double helix?
• When lactose is present, lactose binds to the repressor, inactivating it so it can no longer bind to the operator.
• When lactose is present, RNA polymerase binds to the promoter to transcribe the enzymes needed to digest lactose.
• Where does the assembly of transcription factors begin?