DNA Flashcards
a) Describe a function of telomeres
b) What activity of DNA polymerase I is required for removal of RNA primers during lagging strand synthesis in bacteria
c) What sort of mutation are gain of function mutations usually
d) What happens with missense mutations
e) What happens with nonsense mutations
a) They are required for replication and maintenance of chromosome ends
b) 5’-3’ exonuclease activity
c) Usually autosomal dominant
d) Change a codon to alter the amino acid sequence
e) Change codons encoding an amino acid to a premature stop codon
a) What can splicing mutations do
b) Is telomerase required in prokaryotic DNA replication
c) How long is the linker DNA between adjacent nucleosomes
d) How long are primers
e) What can a genomic library be used for
a) Can create new splice sites or cause exon skipping
b) No
c) Usually less than 100 bp long
d) Generally 15-20 nucleotides long
e) Used to characterise introns and exons
a) How does PCR amplify DNA
b) What does PCR require
c) What can deamination cause in DNA
d) Can deletions of DNA sequences occur during replication
e) Can insertions of DNA sequences occur during replication
a) Exponentially
b) A DNA template, a supply of deoxynucleotide triphosphates (dNTPs), a heat-stable DNA polymerase, DNA primers
c) Cytosine in DNA can be converted to uracil
d) Yes
e) Yes
a) Can mismatched bases be inserted during replication
b) Can replication forks stall during replication
c) How are stalled replication forks resolved
d) What does DNA polymerase catalyse
e) What does DNA polymerase use to synthesise DNA
a) Yes
b) Yes
c) Homologous recombination
d) Addition of a nucleotide to the 5’ end of a DNA primer
e) dNTPs
a) How does replication commonly proceed from an origin
b) What primers does lagging strand DNA synthesis use
c) What is true of any known DNA polymerase
d) What is the function of the primosome
e) What is the function of the proliferating cell nuclear antigen (PCNA)
a) Bi-directionally
b) RNA primers
c) Adds nucleotides to the 3’ end of DNA and requires a primer hydrogen-bonded to the template
d) Synthesises RNA primers
e) Ensures processivity of the leading strand in eukaryotes
a) What defines the origins of replication in eukaryotes
b) What is the helicase that melts DNA at the eukaryotic DNA replication fork
c) What is the polymerase involved in base excision repair in eukaryotes
d) What catalyses the elongation of the leading strand during DNA replication in bacteria
e) What catalyses the recognition and correction of a mismatch error that was not repaired by the DNA polymerase proofreading activity
f) What bacterial enzymes cut DNA at or near specific recognition sequences
a) ORC
b) MCM
c) DNA polymerase β
d) DNA pol III
e) MutS/MSH2
f) Restriction endonuclease
a) What catalyses the removal of uracil in DNA that has arisen by deamination of cytosine
b) What DNA damage repair system critical for double strand break repair in the G0 and G1 phases of the cell cycle
c) What is a DNA repair system that repairs stalled replication forks
d) A human genetic disease caused by mutations in components of the nucleotide excision repair system
e) What protein prevents parental DNA strands from re-annealing during DNA replication
f) What is an RNA-dependent DNA polymerase
a) DNA glycosylase
b) Non-homologous end joining
c) Homologous replication
d) Xeroderma pigmentosum
e) Single strand binding (SSB) protein
f) Telomerase
