Name:Aidan Taylor
Date:_________________
DNA Replication Web Quest
Watch and listen to the animation to answer the following questions as you go along.
http://www.wiley.com/college/pratt/0471393878/student/animations/dna_replication/index.html
1. What is DNA replication?
●
the copying of double-stranded DNA
●
necessary for cell reproduction prior to cell division
2. How does DNA replicate? (Circle One)
i.
Conservatively
ii. ​Semi-Conservatively
iii. Dispersively
a. What does this mean?
Semi-conservative replication means that the two resulting DNA copies will each have only
one strand of
parental DNA and one completely new constructed strand of DNA.
3. Watch and listen to section 3 in its entirety. While you watch, fill in the table below with the purpose that each
molecule serves during the replication process.
Molecule
Purpose
Polymerase
extends DNA chain
Helicase
separates DNA strands
Ligase
links short DNA chains
Primase
creates RNA primers
4. What is the first step of DNA replication?
a. What enzyme was involved in this?
5. What is the replication fork?
6. What does anti-parallel mean?
7. In what direction can DNA polymerase make a new strand of DNA?
a. Why can’t it make a new DNA strand in the other direction?
8. What is needed prior to DNA polymerase synthesis of a new DNA strand?
a. What enzyme creates this?
9. Contrast the leading and lagging strands.
10. The short pieces of DNA formed on the lagging strand are called:
a. What enzyme joins these fragments together?
11. List the 4 events that must occur in the lagging strand prior to completing its replication. In other words, what
needs to happen in order for these fragments to be joined into one continuous strand?
1.
2.
3.
4.
12. Using the space below, summarize the steps of DNA replication in order. Make sure to describe the enzymes
involved in each step.
14. Why is DNA replication said to be semi-conservative? _____________________
________________________________________________________________
15. What enzyme unwinds the DNA strands? ___________________________
16. What is the function of primase? ______________________________________
________________________________________________________________
17. What is the function of polymerase? __________________________________
________________________________________________________________
18. The leading strand is synthesized _________________________, while
the lagging strand is synthesized ___________________________.
19. DNA pieces separated by primers in the lagging strand are called
_____________________________.
Click on ​http://www.yourgenome.org/facts/what-is-dna-replication
14. What holds complementary bases (A & T) together? ________________________
15. The two separated strands will act as ____________________ for making the
_________________________________.
16. One of the strands is oriented in the ___________________________ this is the
________________________. The other strand is oriented in the _____________
________________________ (away from the replication fork), this is the
________________________. As a result of their different orientations, the two strands are
replicated differently:
17. Sketch the image of the DNA replication fork pictured below step 4.