DNA Replication and Transcription Quiz
39 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which type of mutation involves a change in the amino acid due to replacing it with a chemically different amino acid?

  • Nonsense mutation
  • Frameshift mutation
  • Synonymous mutation
  • Missense mutation (correct)

What type of mutation is a result of adding a nucleotide to a coding region?

  • Synonymous mutation
  • Missense mutation
  • Nonsense mutation
  • Frameshift mutation (correct)

Which mutation leads to a premature termination of translation?

  • Missense mutation
  • Frameshift mutation
  • Nonsense mutation (correct)
  • Synonymous mutation

What characterizes a synonymous mutation?

<p>It does not change the amino acid encoded. (D)</p> Signup and view all the answers

Which mutation occurs when a stop codon is mistakenly read as an amino acid?

<p>Nonsense suppressor mutation (A)</p> Signup and view all the answers

What is the initiating codon for protein synthesis?

<p>AUG (C)</p> Signup and view all the answers

After the fourth tRNA enters the ribosome, where will the codon currently in the A site move to?

<p>P-site (C)</p> Signup and view all the answers

The N-terminal amino acid will be connected to the tRNA located in which ribosomal site during protein elongation?

<p>A-site (A)</p> Signup and view all the answers

The Shine-Dalgarno sequence primarily interacts with which component?

<p>Prokaryotic small ribosomal subunits (B)</p> Signup and view all the answers

What is the correct order of events during protein production?

<p>B A E C D (B)</p> Signup and view all the answers

Which type of mutation could cause a mature mRNA to be 300 bases longer than normal?

<p>Intron splicing site mutation (C)</p> Signup and view all the answers

Which event occurs first in the process of protein synthesis?

<p>DNA serves as a template for RNA production (B)</p> Signup and view all the answers

What could cause a change from a UAA codon to a UUA codon?

<p>Silent mutation (A)</p> Signup and view all the answers

What is the purpose of using dideoxy sequencing reactions in DNA analysis?

<p>To determine the nucleotide sequence of DNA. (A)</p> Signup and view all the answers

If dTTP is omitted from the sequencing reactions, which of the following nucleotides would NOT be represented in the final results?

<p>Thymine (C)</p> Signup and view all the answers

What would be observed at the top of the gel after sequencing with all four dideoxynucleotides?

<p>Bands representing the shortest DNA fragments. (B)</p> Signup and view all the answers

Which statement correctly describes the role of ddATP, ddTTP, ddGTP, and ddCTP in the sequencing reactions?

<p>They act as chain termination agents in the sequencing process. (A)</p> Signup and view all the answers

What is the significance of using a primer in dideoxy sequencing?

<p>It provides a starting point for DNA synthesis. (A)</p> Signup and view all the answers

What is the role of a primer in the polymerase chain reaction (PCR)?

<p>To initiate polymerization (A)</p> Signup and view all the answers

Which pair of primers would correctly amplify the provided DNA sequence?

<p>5'-AATCG-3' and 5'-ATTCT-3' (A)</p> Signup and view all the answers

What causes the severe phenotypic effects observed in aneuploidy, such as Down's syndrome?

<p>An imbalance of gene dosage on an extra chromosome (C)</p> Signup and view all the answers

Which genotype is NOT possible when mating a chimeric mouse (A/A;D/d) with a black mouse (a/a;D/D)?

<p>a/a;D/d (D)</p> Signup and view all the answers

When analyzing mutations, what is a characteristic of a point mutation?

<p>It changes a single nucleotide in the DNA sequence (A)</p> Signup and view all the answers

When glucose is absent, what is the enzyme synthesis outcome for the genotype I+P+O+ Z+Y+/I-P-OCZ-Y- with lactose absent?

<p>Neither LacZ nor LacY synthesized (A)</p> Signup and view all the answers

What happens to the synthesis of LacZ and LacY when lactose is present for the genotype I+P-OCZ+Y-/I-O+Z-Y+?

<p>Both LacZ and LacY synthesized (D)</p> Signup and view all the answers

Which of the following statements correctly describes an enhancer?

<p>It is a cis-regulatory sequence that enhances gene expression from a distance. (B)</p> Signup and view all the answers

Which of the following statements is true about reverse transcriptase?

<p>It generates cDNA from eukaryotic mRNA templates. (D)</p> Signup and view all the answers

What would be the synthesis outcome for the genotype IS P+ O+ Z+ Y+ with lactose present?

<p>Neither LacZ nor LacY is synthesized (B)</p> Signup and view all the answers

For the genotype I+P-OC Z+Y-/I- O+Z-Y+ with lactose absent, what is the expected synthesis outcome?

<p>Neither LacZ nor LacY is synthesized (C)</p> Signup and view all the answers

In the context of gene regulation, which option is NOT the function of an enhancer?

<p>It determines the transcription initiation site. (A)</p> Signup and view all the answers

Which statement accurately describes the function of reverse transcriptase?

<p>It synthesizes complementary DNA from RNA templates. (A)</p> Signup and view all the answers

Which statement is true regarding DNA and RNA polymerases?

<p>Both DNA polymerase and RNA polymerase need a primer with a free 3’ end. (D)</p> Signup and view all the answers

What is the function of primase in the context of transcription?

<p>It initiates transcription. (C)</p> Signup and view all the answers

What is needed to connect the fragments produced during DNA replication?

<p>Ligase (B)</p> Signup and view all the answers

Which of the following strands is produced during lagging strand synthesis?

<p>The strand containing Okazaki fragments. (C)</p> Signup and view all the answers

Which of these statements correctly represents the role of telomerase?

<p>It lengthens the lagging strand by extending telomeres. (B)</p> Signup and view all the answers

What is the polarity of the first 6 bases of mRNA transcribed from the provided gene sequence?

<p>5'-GGUCAA-3' (D)</p> Signup and view all the answers

Which of these molecules is responsible for translating mRNA into amino acids?

<p>Ribosome (A)</p> Signup and view all the answers

Based on the provided gene sequence, which organism is the sequence likely derived from?

<p>Eukaryote (B)</p> Signup and view all the answers

Flashcards

Lagging strand synthesis

The process of synthesizing DNA on the lagging strand during replication, which proceeds in short fragments called Okazaki fragments.

Leading strand synthesis

The process of synthesizing DNA continuously on the leading strand during replication.

DNA polymerase

An enzyme that synthesizes DNA by adding nucleotides to an existing DNA strand.

Primase

An enzyme that synthesizes short RNA primers needed for DNA polymerase to start DNA replication.

Signup and view all the flashcards

Telomerase

An enzyme that adds repetitive sequences to the ends of chromosomes to prevent degradation.

Signup and view all the flashcards

Eukaryotic vs. Prokaryotic

Eukaryotic organisms have a nucleus, while prokaryotic organisms do not.

Signup and view all the flashcards

Transcription start site (+1)

The position on a gene where RNA polymerase binds and begins to transcribe.

Signup and view all the flashcards

mRNA codon sequence

A sequence of three nucleotides that codes for a specific amino acid during translation.

Signup and view all the flashcards

Mutation in transcription stop signal

A change in the DNA sequence that affects the signal telling the cell when to stop transcribing a gene.

Signup and view all the flashcards

Frameshift mutation

A mutation that shifts the reading frame of the genetic code, altering the amino acid sequence.

Signup and view all the flashcards

Lac operon

A group of genes in bacteria that work together to regulate the use of lactose as an energy source.

Signup and view all the flashcards

Enhancer

A DNA sequence that increases the rate of transcription of a gene, even if located far away.

Signup and view all the flashcards

Cis-regulatory sequence

A DNA sequence that regulates the expression of nearby genes.

Signup and view all the flashcards

Reverse transcriptase

An enzyme that can create DNA from an RNA template.

Signup and view all the flashcards

Transcription factor

A protein that binds to DNA and regulates the transcription of a gene.

Signup and view all the flashcards

Lac operon regulation (glucose absent)

When glucose is absent and lactose is present, the lac operon gets turned on to help bacteria use lactose for energy.This means the corresponding enzymes are produced.

Signup and view all the flashcards

Initiating Codon

The codon AUG, which is always the first codon in a protein-coding sequence.

Signup and view all the flashcards

mRNA Attachment to Ribosome

Messenger RNA binds to the ribosome to initiate protein synthesis.

Signup and view all the flashcards

Protein Synthesis - tRNA binding to codon

tRNA molecules carry specific amino acids and attach to their corresponding codons on the mRNA.

Signup and view all the flashcards

Shine-Delgarno sequence interaction

The Shine-Delgarno sequence (in prokaryotes) interacts with the small ribosomal subunit's RNA, guiding mRNA binding.

Signup and view all the flashcards

Protein Synthesis Order(steps)

DNA (template) -> RNA production -> mRNA to cytoplasm -> mRNA attach to ribosome -> tRNA attach to codon -> amino acid bonding.

Signup and view all the flashcards

mRNA Length Mutation

A mutation that increases the length of the mature mRNA by 300 bases.

Signup and view all the flashcards

mRNA Location Change

mRNA moves from the nucleus to the cytoplasm for protein synthesis.

Signup and view all the flashcards

mRNA insertion mutation

A mutation that inserts 300 base pairs into the intron of a gene.

Signup and view all the flashcards

PCR primer

A short, single-stranded DNA sequence that binds to a specific region of DNA and initiates DNA replication during PCR.

Signup and view all the flashcards

Aneuploidy

An abnormal number of chromosomes in a cell, often resulting in developmental abnormalities and genetic disorders.

Signup and view all the flashcards

Chimeric mouse

A mouse with cells from two different embryos, leading to a mix of genetically distinct tissues.

Signup and view all the flashcards

Knockout gene

A gene that has been inactivated or deleted, allowing researchers to study the function of the gene.

Signup and view all the flashcards

Dosage effect

The impact on phenotype caused by a difference in the number of copies of a gene.

Signup and view all the flashcards

Missense Mutation

A type of point mutation where a single nucleotide change results in the substitution of one amino acid for another.

Signup and view all the flashcards

Nonsense Mutation

A mutation that changes a codon that normally specifies an amino acid into a stop codon, causing premature termination of protein synthesis.

Signup and view all the flashcards

Synonymous Mutation

A type of point mutation that results in a codon change but does not alter the amino acid sequence of the resulting protein.

Signup and view all the flashcards

Nonsense Suppressor Mutation

A mutation that allows a stop codon to be read as an amino acid, overriding the premature termination signal caused by a nonsense mutation.

Signup and view all the flashcards

Dideoxy Sequencing

A method to determine the nucleotide sequence of a DNA fragment using dideoxynucleotides (ddNTPs) that terminate DNA synthesis.

Signup and view all the flashcards

Gel Electrophoresis

A technique used to separate DNA fragments by size. Smaller fragments travel faster through a gel matrix, resulting in a pattern of bands.

Signup and view all the flashcards

Primer Sequence

A short, single-stranded DNA sequence that binds to a template DNA strand, providing a starting point for DNA polymerase to synthesize a new strand.

Signup and view all the flashcards

ddNTPs: Chain Terminators

Dideoxynucleotides (ddNTPs) lack a 3'-OH group, preventing the addition of further nucleotides and stopping DNA synthesis.

Signup and view all the flashcards

Sequencing Reaction Outcome

The results of dideoxy sequencing show a series of bands on a gel, each corresponding to a specific nucleotide in the DNA sequence.

Signup and view all the flashcards

Study Notes

DNA Replication and Transcription

  • DNA polymerase and RNA polymerase require a primer with a free 3' end for functionality
  • Both leading and lagging strands require primers in DNA replication
  • DNA polymerase only adds nucleotides to an existing DNA strand
  • Primase is required to initiate DNA transcription, not translation
  • Ligase joins DNA fragments, not codons in mRNA

DNA Replication - Chromosome End

  • The sequence shown on the blackboard represents the polarity of a replicated chromosome end
  • Lagging strand synthesis produces one strand
  • Telomerase extends the lower strand

Gene Sequence Analysis

  • The given sequence is likely from a eukaryote, due to the presence of a TATA box
  • mRNA transcribed from the fragment, with 5' to 3' polarity, would be GGUCAA
  • The first three amino acids, resulting from the mRNA translation, would be Met-Lys

Ribosome Translation

  • The codon currently in the E site is AUG
  • After the fourth tRNA enters the ribosome, the codon in the A site will be in the P site
  • The N-terminal amino acid is connected to the tRNA in the A site via covalent bonds

Shine-Delgarno Sequence

  • The Shine-Delgarno sequence interacts with the proteins of only prokaryotic small ribosomal subunits

Protein Production

  • The correct order of protein production events is: DNA serving as a template for RNA production, RNA moving from nucleus to cytoplasm, Messenger RNA attaching to a ribosome, Transfer RNA bonding to a codon, Amino acids bonded together

Gene Mutations

  • A 300 base pair insertion into an intron can cause a mature mRNA that is longer than the normal mature mRNA

Lac Operon

  • The table shows the synthesis of lacZ, lacY, and lacI enzymes in response to the presence or absence of lactose in both cases where the gene is operon or not

Enhancer

  • An enhancer is a cis-regulatory DNA sequence that acts at a distance to promote gene expression

Reverse Transcriptase

  • Reverse transcriptase uses an RNA template to create DNA, requiring a primer for polymerization

PCR Primers

  • A pair of 5 base primers for PCR amplification of the given sequence are 5'-AATCG-3' and 5'-ATTCT-3'

Aneuploidy

  • Aneuploidy, such as trisomy, leads to severe phenotypic effects due to dosage effects arising from the imbalanced gene expression caused by the extra chromosome

Dideoxy Sequencing Reaction

  • A gel electrophoresis diagram that shows sequences based on ddNTP incorporation in DNA synthesis.
  • A second diagram shows the gel electrophoresis if dTTP was not included, thereby highlighting where the sequence is missing dTTP in the reaction results

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Practice Final 2019 Genetic PDF

Description

Test your understanding of the processes involved in DNA replication and transcription. This quiz covers essential concepts, including the roles of various enzymes, the importance of primers, and the characteristics of eukaryotic gene sequences. Challenge yourself on areas such as ribosome translation and telomerase function!

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser