Download DNA Replication

Biology
DNA Replication
Name: _____________ Period: ___ Date:________
Part I: DNA REPLICATION – How DNA is copied.
Use page 297 - 299 in the textbook to answer the following questions (not
in order of the book ).
1. Define DNA replication.
2. When and why does DNA replication occur?
3. According to Watson and Crick’s double helix model the
two strands of DNA are complementary to each other,
what does that mean?
4. What is the role of enzymes in DNA replication?
DNA POLYMERASE
5. What is the result of DNA replication (page 299)?
Biology
DNA Replication
Name: _____________ Period: ___ Date:________
Part II: Notes on DNA Replication:
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Part III: LETTER TO LARRY: DNA REPLICATION – With a bright color
marker highlight the mistakes in poor cousin Larry’s letter. Number
each mistake and write the correct word at the bottom. The number in
parentheses tells your how many errors are in the paragraph!
Dear Cousin,
How’s it going? Did you know that DNA is nicknamed “The Code of
Life?” for real? I’ve been learning all about it in my biology class. It’s so
exciting that I thought I’d share my newly found knowledge with you.
Biology
DNA Replication
Name: _____________ Period: ___ Date:________
(3) As you know, DNA is found within the vacuole of the cell. In
order for each cell to function properly, it must have the correct amount
of DNA. So, before cells divide, the DNA must replicate. DNA replication
is kind of tricky, though, because the square shape of the molecule
prevents contact with enzymes, which are specialized carbohydrate
molecules that help speed up chemical reactions. I’d better take you
through this amazing process step by step.
(5) First, an enzyme unwinds and unzips the DNA molecule.
The unzipping occurs when the ionic bonds between base pairs are
broken and the two strands of the molecule unwind. Each strand serves
as a template for the attachment of complementary bases. Addition of
new amino acids can’t begin, though, until an RNA primer is added by
the enzyme primase. Once primed, DNA polymerase adds new
nucleotides to the DNA molecule. The nitrogen base adenine always
pairs with guanine and cytosine always pairs with thymine. DNA
proofreaderase also “proofreads” each new DNA strand, helping to
maximize the odds that each molecule is a perfect copy of the original
DNA. Pretty cool, huh?
(2) DNA replication results in three molecules of DNA each,
consisting of one parental or template strand and one newly synthesized
strand, thus the strands are known to be compensatory. Isn’t it great?
And to think that this complex process is taking place inside our cells at
this very instant. Well, I hope school is going well and you had a
wonderful Spring Break!!
Cousin Larry
1. ____________________________ 6.______________________________
2. ____________________________ 7. ______________________________
3. ____________________________ 8. ______________________________
4. ____________________________ 9. ______________________________
5. ____________________________ 10. ______________________________
Biology
DNA Replication
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Name: _____________ Period: ___ Date:________