WARM-UP 12/2/15: WRITE THE QUESTIONS AND THE ANSWERS
TO THE QUESTIONS ON A NEW WARM-UP SHEET FOR THE WEEK.
1. Where is DNA found in eukaryotic plant and animal cells? Prokaryotic
cells?
2. DNA is what type of organic molecule?
3. DNA is made from what subunit or building block?
4. What is the function of DNA?
5. Write the complementary base strand for this sequence of DNA: CTA
GGC TTT AGC
6. Describe what happens during G1, S and G2 of the cell cycle.
WARM-UP 12/3/15: WRITE THE QUESTIONS AND THE ANSWERS
TO THE QUESTIONS ON YOUR WARM-UP SHEET FOR THE WEEK.
1. Describe what happens during prophase, metaphase, anaphase
and telophase of mitosis,
2. Your DNA is 99% identical to the person beside you, yet you are
two very different people. Explain how it is possible that human
beings are almost genetically identical, yet they are very
different.
3. DNA bases pair up with their complement. What does
complementary base pairing mean?
TODAY WE WILL…
• Warm-up: DNA Review
• Introduction to DNA Replication
• DNA replication guided notes
• DNA replication video clip
• DNA Replication Concept Map
• DNA Replication Practice
• Test Review
• Exit Ticket
STEPS OF DNA REPLICATION
Adenine
1. An enzyme unzips the 2 DNA
strands by breaking weak
hydrogen bonds
Thymine
2. New nucleotides are added to
the old strands
Cytosine
3. Another enzyme zips the
strands back up
Guanine
4. DNA polymerase (another
enzyme) proofreads the
strands
WHAT IS DNA REPLICATION?
• NEW cells are made by copying
OLD cells
• Before a cell divides, you have to
copy or REPLICATE the DNA
REVIEW!
What stage of the cell cycle does
DNA Replication happen in?
WHEN DOES DNA REPLICATION OCCUR?
During S –Phase of INTERPHASE
• S-Phase = Synthesis Phase
• The DNA Replicates (copies itself ) to prepare for cell
division (MITOSIS!!!)
WHY DOES DNA REPLICATE?
• To get ready for cell division
• So each new cell has the same exact DNA!
WHAT ARE THE STEPS FOR DNA REPLICATION?
1. An Enzyme “UNZIPS” the 2 strands of DNA by breaking the
weak Hydrogen bonds
2. New nucleotides are added to the old stand
• REVIEW: A = T and C = G
3. Another Enzyme “ZIPS” the strands back up
4. DNA Polymerase (an enzyme) “proofreads” the strands to make
sure there are no MISTAKES!
What do you think
might happen if
there are mistakes?!
WHAT IS THE ROLE OF ENZYMES?
• Enzymes help to:
1. Split the DNA in half
2. Put DNA back together
3. Proofread for any mistakes in the base pairs
HOW IS DNA REPLICATION SEMI-CONSERVATIVE?
• When the DNA copies itself, it always has HALF of the
parental (OLD) strand and HALF of the daughter (NEW)
strand
• In other words: the DNA is HALF OLD and HALF NEW
WHAT ARE MUTATIONS?
• Changes in the genetic code (DNA)
• Can be: positive, negative or neutral
• Causes: UV radiation, chemicals, bad DNA proofreading
• Can lead to CANCER
DNA REPLICATION PRACTICE
• DNA strand:
ATGGC
• Complementary DNA strand: _________
DNA REPLICATION
• http://www.youtube.com/watch?v=zdDkiRw1PdU&feature=related
HOW TO FIND A MUTATION…
• Original DNA Sequence:
T A C A C C T T G G C G A C G A C T
• Complementary Strand:
A T C G G G A C C C G C T T G T G A
• Corrected Strand:
DNA REPLICATION CONCEPT MAP: WE WILL CREATE A
CONCEPT MAP TOGETHER TO HELP YOU ORGANIZE THE
PROCESS OF DNA REPLICATION.
INDEPENDENT PRACTICE: DNA REPLICATION
• Quietly and Independently complete your DNA
Replication Practice
DNA EXIT TICKET
UNIT 6 MITOSIS AND ASEXUAL REPRODUCTION TEST
REVIEW
• If you did not finish your cell cycle foldable from
yesterday, please complete this first.
• Next, work on the Unit 6 Test study guide
CELL CYCLE FOLDABLE (OUTSIDE)
1. Interphase
2. Prophase
(Picture)
(Picture)
3. Metaphase
4. Anaphase
(Picture)
(Picture)
Telophase
Cytokinesis
(Picture)
(Picture)
CELL CYCLE FOLDABLE (INSIDE)
1. Interphase
(Description- What is
happening in this stage of
the cell cycle?)
What are the four reasons
that cells divide?
3. Metaphase
(Description- What is
happening in this stage of
mitosis?)
Telophase
Description- What is
happening in this stage of
mitosis?)
What form is DNA when the
cell is NOT dividing?
What form is DNA in when
the cell IS dividing?
2. Prophase
(Description- What is
happening in this stage of
mitosis?)
4. Anaphase
(Description- What is
happening in this stage of
mitosis?)
Cytokinesis
Description- What is
happening in this stage of
the cell cycle?)