Download Supplemental Instruction BY123 Dr. Fischer (session 19

Supplemental Instruction BY123 Dr. Fischer (session 19)
Mysupplemental.yolasite.com | [email protected]
Definitions:
Chromatin:
Heterochromatin:
Euchromatin:
Histone:
Nucleosome:
Ligase:
Nuclease:
Telomere:
Telomerase:
Questions:
The role of DNA polymerases in DNA replication is to
_____.
attach free nucleotides to the new strand
synthesize an RNA primer to initiate DNA strand
synthesis
link together short strands of DNA
separate the two strands of DNA
all of the above
One strand of a DNA molecule has the base sequence 5'-ATAGGT-3'. The complementary base
sequence on the other strand of DNA will be 3'-_______-5'.
TATCCA
TGGATA
TGGAUA
UAUCCA
ATAGGT
DNA polymerase adds nucleotides to the _____ of the leading strands, and to the
_____ of the lagging strands (Okazaki fragments).
5' end; 3' end
3' end; 5' end
5' end; 5' end
3' end; 3' end
sugar group;
phosphate group
What enzyme joins Okazaki fragments?
DNA polymerase
DNA ligase
topoisomerase
helicase
primase
After the formation of a replication bubble, which of the
following is the correct sequence of enzymes used for the
synthesis of the lagging DNA strand?
primase, helicases, DNA polymerase, ligase
helicases, primase, ligase, DNA polymerase
helicases, primase, DNA polymerase, ligase
helicases, DNA polymerase, primase, ligase
ligase, primase, DNA polymerase, helicases
The removal of the RNA primer and addition of DNA
nucleotides to the 3' end of Okazaki fragments in its place
is carried out by _____.
nuclease
primase
DNA polymerase I
DNA polymerase III
ligase
Once the DNA at the replication fork is unwound by
helicases, what prevents the two strands from coming back
together to reform a double helix?
The helicase modifies the DNA in such a way
as to eliminate the affinity between the two
strands.
DNA polymerase follows the helicase so
closely that there is no chance for the strands
to come back together.
Single-strand binding proteins bind the
unwound DNA and prevent the double helix
from reforming.
The helicase pushes the two strands so far
apart that they have no chance of finding each
other.
One of the strands is rapidly degraded,
preventing the double helix from reforming.