CONCEPTUAL APPROACH, 7TH EDITION BY
PIERCE (2024), CHAPTERS 1–26 | ISBN
9781319216801
◉ The model for semiconservative DNA replication was first
suggested/proposed by: Answer: Watson and Crick
◉ Who's experiment first PROVED the semiconservative DNA
replication model? Answer: Messelson and Stahl
◉ Which one of the following statements about DNA polymerase III
of E. coli is not true?
a) It synthesizes new DNA by adding to the 3' end of the growing
chain
b) It requires a primer
c) it possesses a 5' exonuclease activity
d) It possesses a 3' exonucelase activity
e) It synthesizes the majority of the new DNA during chromosome
replication Answer: C) It possesses a 5' exonuclease activity
-nick repair is done by DNA Pol I
,◉ Which of the following enzymes is considered a topoisomerase?
a) DNA Pol I
b) helicase
c) primase
d) DNA gyrase
e) DNA ligase Answer: D) DNA gyrase
◉ What are enzymes that regulate the overwinding or
underwinding of DNA? Answer: Topoisomerases
◉ Which E. coli enzyme removes the primers used in DNA synthesis
(5' exonuclease activity)? Answer: DNA Polymerase I
◉ One strand of the DNA duplex is synthesized in a continuous
fashion. The other is synthesized as a series of relatively short
fragments. This discontinuous method of DNA replication was first
suggested by: Answer: Reiji and Tuneko Okazaki
◉ What is the region of the E. coli cell where the chromosome is
found called? Answer: nucleoid
◉ Studies of the polytene chromosomes found in dipteran salivary
gland cells revealed that chromosome puffs were found: Answer: in
regions of high gene expression activity
,◉ A DNA molecule is found to have MORE than 10.4 base pairs per
turn of the helix. It would be best described as being: Answer:
negatively supercoiled
◉ A DNA molecule is found to have LESS than 10.4 base pairs per
turn of the helix. It would be best described as being: Answer:
positively supercoiled
◉ What is a DNA strand that codes for two alleles called? Answer:
heteroduplex
◉ Which histone is not part of the core particle octamer found in
eukaryotic chromatin? Answer: H1 (entry and exit to core particle)
◉ Which histones are core particles that form tetramers/octamers
found in eukaryotic cells? Answer: H2A
H2B
H3
H4
◉ In the context of eukaryotic chromatin, the 11 nm fiber is:
Answer: A string of nucleosomes (nm)
, ◉ In the context of eukaryotic chromatin, the 2 nm fiber is: Answer:
The DNA double helix
◉ In the context of eukaryotic chromatin, the 30 nm fiber is:
Answer: a coil of nucleosomes with about 6 per turn
◉ In the context of eukaryotic chromatin, the 300 nm fiber is:
Answer: a repeatedly folded fiber
◉ The 3' exonuclease activity of E. coli DNA polymerase I is very
important in that it allows the enzyme to: Answer: proofread
◉ The 5' exonuclease activity of E. coli DNA polymerase I is very
important in that it allows the enzyme to: Answer: Carry out nick
translation during DNA repair
◉ An example of a gene or genes commonly present in genomes at
more than one copy per haploid equivalent would be: Answer: rRNA
genes
◉ Today's DNA profiling technology relies upon loci called: Answer:
STRs (Short Tandem Repeats)
(microsatellites)