Molecular Biology Quiz
18 Questions
6 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

What is the primary function of a telomere?

  • Chromosome replication
  • Protecting chromosome ends from degradation (correct)
  • Regulating gene expression
  • DNA repair

Which enzyme is responsible for synthesizing RNA primers during DNA replication?

  • RNA polymerase
  • Primase (correct)
  • Helicase
  • DNA polymerase

Which of the following is true about euchromatin?

  • It is densely packed and stained darkly
  • It is the site of active gene expression (correct)
  • It is exclusively found in prokaryotic cells
  • It is transcriptionally inactive

Which DNA sequence is recognized by restriction enzymes?

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

What mechanism ensures dosage compensation in mammals?

<p>X-inactivation (C)</p> Signup and view all the answers

What is the basic unit of chromatin structure?

<p>Nucleosome (D)</p> Signup and view all the answers

Which type of genetic variation is associated with microsatellites?

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

What is the genetic material of retroviruses?

<p>Single-stranded RNA (A)</p> Signup and view all the answers

Which method is used to detect large blocks of DNA repeats organized in tandem arrays?

<p>Restriction endonuclease digests and microsatellite DNA polymorphism (A)</p> Signup and view all the answers

What percentage of the human genome is composed of protein-coding exons?

<p>Less than 2% (C)</p> Signup and view all the answers

What key knowledge is required for positional cloning?

<p>Map location of a gene (B)</p> Signup and view all the answers

At which level does the regulation of gene expression occur in eukaryotic cells?

<p>At every stage including post-translation (A)</p> Signup and view all the answers

Which agarose gel concentration is suitable for fractionating uncut genomic DNA?

<p>1.5% (C)</p> Signup and view all the answers

What substance mimics allolactose to remove the lac repressor protein in E. coli?

<p>Isopropyl β-D-1-thiogalactopyranoside (IPTG) (D)</p> Signup and view all the answers

What type of DNA sequences were identified by density gradient ultracentrifugation in eukaryote genomes?

<p>Tandemly arrayed repetitive DNA sequences called satellite DNA (B)</p> Signup and view all the answers

What defines heterochromatin in genomic structures?

<p>Repetitive regions of the DNA (A)</p> Signup and view all the answers

How has the understanding of 'one gene one protein' changed?

<p>Because of alternative splicing (D)</p> Signup and view all the answers

What is considered a main source of genetic variation?

<p>Mutations and gene flow (D)</p> Signup and view all the answers

Flashcards

What are telomeres?

Telomeres are protective caps at the ends of chromosomes, preventing degradation and ensuring chromosome stability during replication.

What does primase do?

Primase synthesizes short RNA primers on the DNA template, providing a starting point for DNA polymerase to begin replication.

What is euchromatin?

Euchromatin is the less condensed form of chromatin, allowing for active gene expression.

What do restriction enzymes do?

Restriction enzymes recognize and cut specific palindromic DNA sequences, acting as molecular scissors for DNA manipulation.

Signup and view all the flashcards

How is dosage compensation achieved in mammals?

X-inactivation in females ensures equal dosage of X-linked genes by silencing one X chromosome, creating a Barr body.

Signup and view all the flashcards

What is non-coding RNA?

Non-coding RNA does not directly code for proteins, but plays vital roles in gene regulation, translation, and other cellular processes.

Signup and view all the flashcards

What is the role of the centromere?

The centromere is the constricted region of a chromosome that serves as the attachment point for spindle fibers during cell division.

Signup and view all the flashcards

What is the function of a promoter?

A promoter is a DNA sequence that signals the start of a gene, allowing RNA polymerase to bind and initiate transcription.

Signup and view all the flashcards

Satellite DNA

Repetitive DNA sequences arranged in tandem arrays.

Signup and view all the flashcards

Positional Cloning

A method used to map and identify genes based on their location in the genome.

Signup and view all the flashcards

Agarose Gel Electrophoresis

The process of separating DNA fragments based on their size using an electric current in a gel matrix.

Signup and view all the flashcards

Isopropyl β-D-1-thiogalactopyranoside (IPTG)

A molecular mimic of allolactose, used to induce gene expression through the lac operon.

Signup and view all the flashcards

Heterochromatin

Regions of DNA that are densely packed and transcriptionally inactive.

Signup and view all the flashcards

One gene one protein

The principle that one gene codes for one protein, has been expanded by the discovery of alternative splicing.

Signup and view all the flashcards

Evolution

The continuous ongoing process of evolution that drives changes in species over time.

Signup and view all the flashcards

Genetic Drift

The process of changing the genetic makeup of a population due to random fluctuations in gene frequencies.

Signup and view all the flashcards

Gene Flow

The introduction of new genetic variation into a population from other populations.

Signup and view all the flashcards

Phenotypic and Genotypic Variation

The sources of variation that contribute to differences in traits and genetic makeup within a population.

Signup and view all the flashcards

Study Notes

Multiple Choice Questions

  • Telomere function: Protects chromosome ends from degradation
  • RNA primer synthesis enzyme: Primase
  • Euchromatin characteristic: Site of active gene expression
  • Restriction enzyme recognition sequence: Palindromic sequences
  • Dosage compensation mechanism in mammals: X-inactivation
  • Non-coding RNA example: tRNA
  • Spindle fiber attachment structure: Centromere
  • Promoter function: Binds RNA polymerase to initiate transcription
  • Transposable element using RNA: Class I elements
  • Chromatin unit: Nucleosome
  • Microsatellite variation type: Tandem repeats
  • Hardy-Weinberg equilibrium assumption: Large population size
  • Retrovirus genetic material: Single-stranded RNA
  • Start codon function: Specifies where to begin translation
  • Frameshift mutation type: Insertion or deletion

Short Answer Questions (SAQ) - Part A

  • Large DNA repeat analysis method: Restriction endonuclease digests and microsatellite DNA polymorphism
  • Percentage of human genome contributing to protein-coding exons: Less than 2%
  • Positional cloning prerequisite: Knowledge about the map location of a gene
  • Eukaryote gene expression regulation: At every stage, from histone modification in chromatin, transcription factors, mRNA processing, mRNA transport, and storage to translation.
  • Agarose gel electrophoresis for genomic DNA: 1.5% agarose concentration
  • Molecular mimic of allolactose in DH5α E. coli: Isopropyl β- d-1-thiogalactopyranoside (IPTG)
  • Major component identified in eukaryote genome analysis: Tandemly arrayed repetitive DNA sequences (satellite DNA)
  • Heterochromatin: Repetitive regions of DNA
  • "One gene, one protein" principle modification: Due to alternative splicing
  • Sources of phenotypic and genotypic variation: All answers are correct (implied)

Short Answer Questions (SAQ) - Part B

  • Is evolution finished? No. Evolution is a continuous process driven by natural selection, mutation, genetic drift, gene flow, and recombination.
  • Examples of ongoing evolution:
  • Bacteria and drug resistance: Emergence of antibiotic-resistant bacteria (e.g., MRSA).
  • Human evolution: Lactose tolerance (mutation in the LCT gene in populations with dairy farming), skin pigmentation adaptation.
  • Climate change and animal adaptation: Hybridization of Arctic animals (e.g., polar bears and grizzly bears) to changing environments.
  • Artificial selection: Development of disease-resistant crop varieties.
  • Conclusion: Evolution will continue due to genetic variation and changing environments.

Studying That Suits You

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

Quiz Team

Description

Test your knowledge on key concepts of molecular biology, including telomere functions, RNA synthesis, and gene expression mechanisms. This quiz covers essential topics such as chromosome structure, genetic mutations, and the molecular functions of various nucleic acids.

More Like This

Molecular Biology Fundamentals Quiz
3 questions
Biology Chapter on Nucleic Acids
67 questions

Biology Chapter on Nucleic Acids

ThrillingStarlitSky3436 avatar
ThrillingStarlitSky3436
Use Quizgecko on...
Browser
Browser