What is DNA . DNA versus RNA

1. DNA: Replication and Mutation

2. What is DNA?
 DNA = deoxyribonucleic acid
 DNA is the “blueprint” for the cell
contains the instructions that tells the
cell how to do things and what to make
 DNA is like blueprints for making a city, which
in this case is the cell
RED => COPY INTO NOTEBOOK
Amoeba Cell

3. What is DNA made of?
 DNA is made up of 4 bases:
– Adenine (A), Thymine (T), Cytosine (C), Guanine (G)
Rules for DNA Bases:
1. A pairs with T
2. G pairs with C
“Chargaff’s Rules”

4. Structure of DNA
 DNA is made up of two
strands (double
stranded)
 Each strand has the
bases connected to a
PHOSPHATE
BACKBONE
 The two strands wrap
around each other in a
winding staircase
manner (helix)

5. Models of DNA

6. ACTUAL Pictures of DNA

7. DNA Replication
 In order for you to survive,
your cells need to replicate
themselves. In order for
them to do that, they need
to replicate their DNA
 Every cell in your body has
the same DNA, because
every time one of your cells
divides, it makes a copy of
its DNA to give to the new
daughter cells

8. How does DNA replicate?
 The DNA is unzipped and the original strands
are used to help make the new molecules –
See Demonstration

9. What are mutations?
 MUTATIONS are any
changes in the
sequence of bases of
DNA
Mutations DO NOT
lead to this
Mutations COULD
lead to this
Colon cancer cells

10. How do mutations occur?
 Sometimes during replication,
the cell makes a mistake and
adds the wrong base
 When the cell replicates its DNA
again, the two strands that are
produced are no longer exactly
the same
 This usually will cause the new
cell to die, but sometimes it can
cause the cell to divide when it is
not supposed to  cancer

11. How do mutations occur?
Replication

12. What can cause mutations to happen
more often?