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DNA Replication Illustrations Name Per. ________ Date ________
Below are the steps of DNA replication which take place during the S stage of Interphase. In each box, read what is taking place and follow the
given directions. Pay attention to the specific coloring directions. Use chapter 12 (Section 2) in your book to help you.
DOUBLE HELIX MOLECULE
Label the following: Nitrogen Base Pair Sugar/Phosphate Backbone Color: Draw a thick BLUE line over each helix strand to represent the original strands
UNWOUND DNA MOLECULE
Label the following: Deoxyribose Sugar Phosphate The “Missing” Bases Color: Sugars – ORANGE A’s – GREEN ; T’s – PINK C’s – RED ; G’s - PURPLE
UNZIPPED DNA MOLECULE
Label the following: The “Missing” Bases DNA Helicase Color: Sugars – ORANGE A’s – GREEN ; T’s – PINK C’s – RED ; G’s - PURPLE
REPLICATING DNA
Label the following: The “Newly Added” Bases DNA Polymerase (2x) Color: All original bases BLUE All newly added bases YELLOW
REPLICATED DNA
Color: (Keep in mind, DNA spirals) Original Backbone BLUE New Backbone YELLOW G A T C C G T T A C
Old New
New Old
C T A G G C A A T G
Name ___________________________________________________ Date ___________________ Period ______
DNA Replication Notes
- Observe the model of DNA. Use the box below to write what you know about its structure.
- Can you remember? When does DNA replication take place during the cell cycle (be specific!)? S STAGE OF INTERPHASE
- Where does replication DNA replication take place within the cell? Hint: think about where DNA is found! NUCLEUS
- Form a hypothesis. How do you think a cell goes from having one molecule of DNA to two molecules of DNA? Keep in mind, it is very important for these molecules to be completely identical to each other. DNA Replication – The Process
- What is the overall purpose of DNA replication?
DNA DNA
- In order for replication to take place, DNA must first unwind and ____ UNZIP ___. a. Which enzyme is responsible for this? DNA HELICASE b. The sites where DNA “separates” for replication are known as ____ REPLICATION FORKS _____.
- Each original strand of DNA will now serve as a ___ TEMPLATE _______ for the new strand.
- The new, ___ COMPLEMENTARY ____ nucleotides must now be added to the original strand. a. Which enzyme is responsible for building the new strand? DNA POLYMERASE
- If the original strand of DNA contains the following sequence: G T C A T T C G A , what would be the sequence of complementary nucleotides added during replication? CAG TAA GCT
- In reality, this is taking place in many locations at once. This creates __ OKAZAKI FRAGMENTS ____. a. Which enzyme is responsible for putting these pieces together?
DNA LIGASE
SHAPE – DOUBLE HELIX
BACKBONE – ALTERNATING SUGARS AND PHOSPHATES
STEPS – NITROGEN BASE PAIRS ATTACHED TO SUGAR
ADENINE PAIRS WITH THYMINE
CYTOSINE PAIRS WITH GUANINE
