BIOC0005 EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
What is the function of alkaline phosphatase in DNA recombination?
Alkaline phosphatase removes the 5' phosphate from the DNA to produce a 5' -OH
meaning it is unable to form a phosphodiester bond and so a plasmid cannot religate
during DNA recombination.
Why are GC rich regions of DNA difficult to sequence?
Because GC base pairs have 3 H-bonds which are difficult to separate.
What is the function of ethidium bromide?
Ethidium bromide allows DNA to be visualised during agarose gel electrophoresis since
it intercalates between stacked bases and then fluoresces under UV light.
What colour does ethidium bromide fluoresce when exposed to UV light?
Orange/red.
What colour does GelRed fluoresce when exposed to UV light?
Orange/red.
What is the difference between ethidium bromide and GelRed?
GelRed isn't mutagenic and so is safer to use in the lab.
What is the function of GelRed?
GelRed is a modified, non-mutagenic form of ethidium bromide which intercalates
between stacked bases and then fluoresces under UV light.
What is a cDNA library?
, A genomic library of protein-coding genes formed from mRNA which is converted to
cDNA by reverse transcription.
What is a genomic library?
A complete collection of all DNA fragments from an organism formed from chromosomal
DNA.
How is %w/v calculated?
(g of solute/100ml of solution)x100
How is %v/v calculated?
(ml of solute/100ml of solution)x100
What is Chargaff's rule?
Charfgaff's rule is that, in DNA, the number of adenine bases is equal to the number of
tyrosine whilst the number of guanine is equal to the number of cytosine.
At what position in what sequence does EcoR1 cleave DNA?
5'-G/AATTC-3'
At what position in what sequence does Pst1 cleave DNA?
5'-CTGCA/G-3'
At what position in what sequence does Hpa1 cleave DNA?
5'-GTT/AAC-3'
Are all plasmids circular?
No, some plasmids can be linear - although this is rare.
What are three main differences between a plasmid and a chromosome?
Plasmids are generally smaller, non-essential for normal growth and more mobile when
compared to chromosomes.
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
What is the function of alkaline phosphatase in DNA recombination?
Alkaline phosphatase removes the 5' phosphate from the DNA to produce a 5' -OH
meaning it is unable to form a phosphodiester bond and so a plasmid cannot religate
during DNA recombination.
Why are GC rich regions of DNA difficult to sequence?
Because GC base pairs have 3 H-bonds which are difficult to separate.
What is the function of ethidium bromide?
Ethidium bromide allows DNA to be visualised during agarose gel electrophoresis since
it intercalates between stacked bases and then fluoresces under UV light.
What colour does ethidium bromide fluoresce when exposed to UV light?
Orange/red.
What colour does GelRed fluoresce when exposed to UV light?
Orange/red.
What is the difference between ethidium bromide and GelRed?
GelRed isn't mutagenic and so is safer to use in the lab.
What is the function of GelRed?
GelRed is a modified, non-mutagenic form of ethidium bromide which intercalates
between stacked bases and then fluoresces under UV light.
What is a cDNA library?
, A genomic library of protein-coding genes formed from mRNA which is converted to
cDNA by reverse transcription.
What is a genomic library?
A complete collection of all DNA fragments from an organism formed from chromosomal
DNA.
How is %w/v calculated?
(g of solute/100ml of solution)x100
How is %v/v calculated?
(ml of solute/100ml of solution)x100
What is Chargaff's rule?
Charfgaff's rule is that, in DNA, the number of adenine bases is equal to the number of
tyrosine whilst the number of guanine is equal to the number of cytosine.
At what position in what sequence does EcoR1 cleave DNA?
5'-G/AATTC-3'
At what position in what sequence does Pst1 cleave DNA?
5'-CTGCA/G-3'
At what position in what sequence does Hpa1 cleave DNA?
5'-GTT/AAC-3'
Are all plasmids circular?
No, some plasmids can be linear - although this is rare.
What are three main differences between a plasmid and a chromosome?
Plasmids are generally smaller, non-essential for normal growth and more mobile when
compared to chromosomes.
