DNA Replication Quiz
1. When comparing the three key models of DNA replication, the model that included the separation of the two strands of the original DNA (template) and using those strands as templates to synthesize two new DNA strands is called:
2. Which of the following is true for replication in both prokaryotes and eukaryotes?
IT IS SEMICONSERVATIVE, IT USES OKAZAKI FRAGMENTS, IT USES A REPLICATION FORK
3. DNA synthesis take place by:
ADDITION OF THE INCOMING NUCLEOTIDE TO THE 3’ OH OF THE GROWING DNA STRAND
4. The complexity of lagging strand replication is necessary because:
AS POLYMERIZATION OCCURS ONLY IN THE 5’ TO 3’ DIRECTION, THE LAGGING STRAND MUST BE SYNTHESIZED IN CONSECUTIVE SMALL FRAGMENTS
5. Which of the following proteins are NOT located at the replication fork during DNA replication?
PRIMASE, DNA POLYMERASE I, DNA POLYMERASE III, HELICASE, AND DNA LIGASE
6. Topoisomerase and helicase have distinct functions. Which of the following statements is correct?
HELICASE IS RESPONSIBLE FOR UNWINDING THE DOUBLE HELIX (SEPARATING STRANDS)
7. Initiation of replication occurs at an “origin of replication” site that typically includes an AT-rich region. Initiation benefits from these AT-rich regions because
ADENINE-THYMINE PAIRS ARE HELD TOGETHER BY TWO H-BONDS, MAKING THEM EASIER TO SEPARATE DURING UNWINDING
8. Which of the following enzyme activities is/are involved in the “Proof reading” function of DNA polymerases I and III?
3’ TO 5’ EXONUCLEASE
9. Which of the following activity or activities does DNA Polymerase I, the polymerase responsible for maturation of Okazaki Fragments, have?
5’-3- POLYMERASE, 3’-5’ EXONUCLEASE, AND 5’-3’ EXONUCLEASE
10. Which of the following enzymes are involved in DNA synthesis of the lagging strand?
DNA POLYMERASE I, DNA POLYMERASE III, PRIMASE, AND LIGASE
11. Experiments on chromosome structure and function have shown that in eukaryotic chromatids:
THERE IS MORE THAN ONE DNA REPLICATING POINT PER CHROMATID
12. When replicating the end of a chromosome, the lagging strand cannot copy the last ~10 nucleotides at the end of the chromosome. As a result, chromosomes contain telomere sequences at their ends, which are defined as:
NON-CODING, REPETITIVE SEQUENCES THAT CAN BE COPIED INDEPENDENT OF THE REPLISOME