How many lectures are in BIO131?
There are 14 lectures in BIO131.
What sessions make up the BIO131 practical component?
Two four-hour practical sessions on nucleic-acid and protein electrophoresis.
What attendance is required to validate BIO131?
Students must attend all lectures, tutorials, and practical sessions.
What happens if a student has an unjustified absence in BIO131?
It prevents validation of the module, semester, and year.
What percentage of the final grade do practical sessions contribute in BIO131?
Practical sessions contribute 30% of the final module grade.
How much is the week-43 multiple-choice test worth in BIO131?
It contributes 20% to the final module grade.
What is the weight of the week-51 final examination in BIO131?
The final examination contributes 50% of the final grade.
What must students bring to each BIO131 practical session?
Students must bring their practical booklet and their own lab coat.
Who discovered nuclein in 1869?
J. F. Miescher discovered nuclein in 1869.
What did Avery, Hershey, and Chase establish in 1952?
They established that DNA carries genetic information.
Who described the DNA double helix in 1953?
Watson, Crick, Wilkins, with Rosalind Franklin's contribution described the DNA double helix.
When was the Nobel Prize awarded for the DNA double helix discovery?
The Nobel Prize was awarded in 1962.
What does the central dogma state about DNA replication and transcription?
DNA directs its own replication and transcription into RNA.
According to the central dogma, what does RNA direct?
RNA directs translation into proteins.
Can information transfer from protein to protein or nucleic acid occur?
No, information cannot transfer from protein to protein or nucleic acid.
What three components make up a nucleotide?
A pentose sugar, a nitrogenous base, and one or more phosphate groups.
How is a nucleoside formed?
By a pentose sugar covalently linked to a nitrogenous base through an N-glycosidic bond.
Which bases does DNA contain?
Adenine, thymine, guanine, and cytosine.
Which bases does RNA contain?
Adenine, uracil, guanine, and cytosine.
What does a 3′–5′ phosphodiester bond link in nucleic acids?
The 3′ hydroxyl of one pentose to the 5′ hydroxyl of the next pentose.
What polarity do phosphodiester bonds give to nucleic-acid strands?
They give nucleic-acid strands their polarity.
How are DNA strands oriented relative to each other?
DNA strands are antiparallel.
In which direction does DNA polymerization proceed?
From 5′ to 3′ by adding nucleotides to a 3′ hydroxyl end.
How many chromosome pairs do human cells have?
23 chromosome pairs.
How many base pairs does Escherichia coli's chromosome have?
Approximately 4 × 10⁶ base pairs.
What shape is mitochondrial DNA in animal eukaryotic cells?
Circular.
What shape is nuclear DNA in animal eukaryotic cells?
Linear chromosomes.
What shape is chloroplast DNA in plant cells?
Circular.
How is eukaryotic DNA compacted into nucleosomes?
By wrapping 146 base pairs around a histone octamer.
What are the main cytoplasmic RNA categories?
rRNA, tRNA, and mRNA.
Which cytoplasmic RNA represents about 80% of total RNA?
rRNA.
What is the melting temperature (Tm) of DNA?
The temperature where 50% of DNA molecules become single stranded.
What does the Beer–Lambert law relate in spectrophotometry?
Absorbance to concentration using .
At which wavelength are nucleic acids quantified?
At 260 nm wavelength.
What does the A260/A280 ratio assess?
Protein contamination in nucleic acid samples.
What A260/A280 ratio indicates pure DNA?
A ratio between 1.8 and 2.
What does an A260/A280 ratio below 1.7 indicate?
Protein contamination in the DNA solution.
What does an A260/A280 ratio above 2 indicate?
RNA contamination in the DNA solution.
How is DNA replication described in terms of strand conservation?
DNA replication is semiconservative.
From where does DNA replication initiate and how does it proceed?
It starts from one origin and proceeds bidirectionally.
Where do DNA polymerases add nucleotides during replication?
Only to a primer-bound template at a 3′ hydroxyl end.
In which direction does newly synthesized DNA grow?
From 5′ to 3′ direction.
How is the lagging strand synthesized during DNA replication?
As 150–200-nucleotide Okazaki fragments starting with RNA primers.
Which enzyme joins Okazaki fragments on the lagging strand?
DNA ligase joins Okazaki fragments.
What components does PCR use to amplify DNA?
PCR uses thermostable Taq polymerase, two primers, and thermal cycles.
How many DNA copies does 20 PCR cycles theoretically produce?
About 2²⁰ or approximately 10⁶ copies of the initial duplex.
In which direction does transcription copy the DNA template strand?
From 5′ to 3′ direction.
Which RNA polymerase transcribes mRNA genes in eukaryotes?
RNA polymerase II.
How is eukaryotic pre-mRNA stabilized?
By 5′ capping, poly(A) tail addition, and intron splicing.
Where does translation occur in the cell?
In the cytoplasm.
What is the first stage of translation?
Initiation at an AUG codon.
What happens during elongation in translation?
Codon reading and amino-acid addition.
What triggers termination in translation?
A stop codon.
What does a genomic library represent compared to a cDNA library?
A genomic library represents the entire genome, while a cDNA library represents only expressed transcripts.
What is the first step in cloning a gene?
Isolating the gene is the first step in cloning.
What is the final step after replicating a gene in a host organism during cloning?
The gene is analyzed after replication in the host.
Name one application of genetic engineering methods.
Genetic engineering can create genetically modified organisms.
What is a restriction enzyme?
A restriction enzyme is a restriction endonuclease that cleaves both DNA strands at a specific recognition site.
What are the main steps in plasmid cloning?
Plasmid cloning involves restriction digestion, ligation, bacterial transformation, selection, and amplification.
What is a plasmid?
A plasmid is a small circular, double-stranded, autonomous, extrachromosomal bacterial DNA molecule.
What key components does a plasmid cloning vector contain?
It contains an origin of replication, selectable resistance genes, and a multiple cloning site.
What does agarose-gel electrophoresis separate DNA fragments by?
By their size.
What is the purpose of a molecular-weight marker in agarose-gel electrophoresis?
To provide fragments of defined lengths for calibration.
What does Southern blotting transfer to a membrane?
Separated DNA fragments.
How does Southern blotting detect a complementary DNA sequence?
By hybridization with a labeled probe.
What does Sanger sequencing detect to verify a cloned insert?
Fluorescence signals from incorporated chain-terminating nucleotides.
Which author is associated with the sequencing method detecting fluorescence from chain terminators?
Sanger.
Name one principal molecular-biology enzyme activity.
Polymerase.
Name another principal molecular-biology enzyme activity besides polymerase.
Exonuclease.
Test your knowledge with 35 questions on BIO131 Nucleic Acids and Molecular Biology.
1. Which combination accurately describes the BIO131 teaching schedule?
2. What is the consequence of an unjustified absence from a BIO131 session?
Review the complete course in the study sheet for BIO131 Nucleic Acids and Molecular Biology.
See study sheet →Import your course and AI generates flashcards in 30 seconds.
Flashcard generator