chapter 11 Testbank Flashcards
Which of the following statements is FALSE about telomeres and the process of replicating telomeres?
Select one:
a. The 5’ end of the telomere is single-stranded, which is called a 5’ overhang.
b. The telomerase protein contains a piece of RNA that is complementary to the repeating unit of the telomere.
c. Telomeres are only found on eukaryotic chromosomes.
d. Telomeres are composed of tandemly repeating units.
e. The enzyme component of telomerase is called TERT, and it is responsible for making DNA from RNA.
a. The 5’ end of the telomere is single-stranded, which is called a 5’ overhang.
The following list the events in one round of replicating the telomeres, but they are not listed in the correct order. Choose the correct order of events from the list provided.
i. Telomerase moves 6 nucleotides to the right.
ii. The RNA segment of telomerase forms complementary base pairs with the telomere.
iii. TERT adds deoxyribonucleotides to the 3’OH end of the 3’ overhang, making DNA from an RNA template.
iv. Telomerase binds to the single-stranded region of the telomere.
Select one:
a. i, vi, ii, iii
b. i, iii, iv, ii
c. iv, ii, iii, i
d. iii, i, ii, vi
e. if none of the responses provided is the correct order, then choose this response.
c. iv, ii, iii, i
Which of the following statements is FALSE regarding telomerase and the replication of telomeres?
Select one:
a. Telomerase activity tends to lessen with age.
b. Telomeres tend to lengthen with age.
c. Cancer cells have highly active telomerase.
d. A newborn has longer telomeres than an elderly person.
e. Cells become senescent (step dividing) when telomeres are short.
b. Telomeres tend to lengthen with age.
Which of the following best describes the double-helix of DNA?
Select one:
A. The strands are complementary
B. It has directionality
C. The strands are arranged in an anti-parallel arrangement
D. All of the answers are correct
D. All of the answers are correct
This enzyme in replication prevents supercoiling ahead of the replication fork.
Select one: A. DNA primase B. Gyrase (the textbook also calls this enzyme topoisomerase) C. DNA ligase D. DNA polymerase I E. DNA polymerase III
B. Gyrase (the textbook also calls this enzyme topoisomerase)
This enzyme manufactures a 10-12 base segment of RNA in the early stages of replication.
Select one: A. DNA polymerase B. Primase C. gyrase/topoisomerase D. DNA ligase E. peptidyl transferase
B. Primase
This enzyme fills in small gaps in the DNA with deoxynucleotides where the RNA primers were located.
Select one: A. DNA polymerase B. Primase C. RNA polymerase D. Gyrase/topoisomerase E. DNA ligase
A. DNA polymerase
——–Your book distinguishes between DNA polymerase III, which is the version that makes most of the DNA, and DNA polymerase I, which is responsible for filling in the gaps made by removing the primer.
This enzyme is responsible for the majority of DNA replication.
Select one: A. helicase B. Topoisomerase/gyrase C. peptidyl transferase D. DNA ligase E. Primase F. DNA polymerase
F. DNA polymerase
This enzyme attaches adjacent Okazaki fragments, forming a continuous DNA strand.
Select one: A. DNA ligase B. Topoisomerase/gyrase C. Helicase D. Primase E. DNA polymerase
A. DNA ligase
This enzyme synthesizes the lagging strand of the DNA.
Select one: A. DNA polymerase B. helicase C. DNA ligase D. DNA primase E. Topoisomerase/gyrase
A. DNA polymerase
DNA polymerases add new nucleotides in what direction?
Select one:
A. 5’ to 3’
B. 3 ‘ to 5’
C. Both directions
A. 5’ to 3’
The purpose of DNA replication is to produce ________.
Select one: A. Two parental strands B. Two template strands C. Two daughter strands D. None of the answers are correct
C. Two daughter strands
Okazaki fragments do which of the following?
Select one:
A. Assist in forming the replication fork
B. Assist in the synthesis of DNA from the lagging strand
C. Reform the double-helix following replication
D. Bind to the oriC region
E. None of the answers are correct
B. Assist in the synthesis of DNA from the lagging strand
Which of the following best describes the mechanism of DNA replication in which both parental strands remain together following replication?
Select one: A. Conservative B. Dispersive C. Semi-conservative D. All of the answers are correct
A. Conservative
Which of the following is/are a restriction placed on the function of DNA polymerase? Choose all that apply.
Select one or more:
A. DNA polymerases must have a template strand to copy from.
B. DNA polymerase must make the newly synthesizing strand in the 5’ to 3’ direction.
C. DNA polymerase must read the template strand in the 3’ to 5’ direction.
D. DNA must choose the first nucleotide in the newly synthesizing strand.
E. DNA polymerase can only make a phosphodiester bond between two nucleotides.
F. DNA polymerase must begin DNA synthesis at a double-stranded region on the chromosome.
G. DNA polymerase must add deoxyribonucleotides to the 3’ end of the newly synthesizing strand.
A. DNA polymerases must have a template strand to copy from
C. DNA polymerase must read the template strand in the 3’ to 5’ direction.
E. DNA polymerase can only make a phosphodiester bond between two nucleotides.
G. DNA polymerase must add deoxyribonucleotides to the 3’ end of the newly synthesizing strand.
DNA polymerases are unable to bind to what areas of the chromosome?
Select one:
A. Origins of replication
B. 3’ end of telomeres
C. Centromeres
B. 3’ end of telomeres
Which of the following best describes the mechanism of DNA replication in which both a parental strand and daughter strand are combined following replication?
Select one: A. Semi-conservative B. Conservative C. Dispersive D. All of the answers are correct
A. Semi-conservative
Bacterial DNA has how many origins of replication?
Select one: A. 0 B. 10 C. 1 D. Depends on the size of the DNA
C. 1
DNA helicase enzymes move in what direction along the DNA during DNA replication?
Select one:
A. 3’ to 5’
B. 5’ to 3’
C. They remain stationary
B. 5’ to 3’
The image below shows two types of replication. Is the following statement TRUE or FALSE. Type 1 replication is illustrating how replication starts on a eukaryotic chromosome, while Type 2 is illustrating how replication starts on a prokaryotic chromosome.
Select one:
True
False
False
DNA polymerase III has the ability to begin synthesis of the new daughter strands immediately following the formation of the replication fork.
Select one:
True
False
False
The origin of replication in bacteria is called OriC.
Select one:
True
False
True
The movement of the replication fork in bacterial replication is unidirectional.
Select one:
True
False
False
After the action of the helicase, single-stranded binding proteins keep the parental DNA strands from reforming a double-helix.
Select one:
True
False
True
The synthesis of the daughter strand of DNA occurs away from the replication fork in the leading strand.
Select one:
True
False
False
The problem in synthesizing the 3’ end of chromosomes is solved by the use of the telomerase enzyme.
Select one:
True
False
True
