Student Assessment:

Draw DNA and a Replication Bubble

In your Replication bubble you must have these terms labeled.

-DNA Helicase

-DNA Polymerase

-DNA Primase

-RNA Primer

-DNA Ligase

- 5' (5 prime) and 3' (3 prime)

-Parent Strand

-Daughter Strand

-Leading Strand

-Lagging Strand

-Replication Fork

-Replication Bubble

Number them and on the back of your paper give a simple sentence explaining what it is or what it does.

Lecture:

Mutations

-A mutation is a change in the sequence of DNA bases

-There are repair enzymes that proof read the new daughter strands to check for errors

-When an error is found it is repaired

-But sometimes these errors are not repaired in the right way and this leads to a mutation

-There are many types of mutations

-Nucleotide Substitutions are when a single base pair is substituted

-For example an A-T base pair is substituted for a T-A

-This is also known as a point mutation because only one base pair is affected

-Insertion Mutations are when extra bases are added to the DNA

-It could be one base pair or it could be many

-Deletion Mutations are when base pairs are deleted

-It could be one base pair or many

-A deletion mutation or an insertion mutation can cause what we call a frame shift mutation

-A frame shift mutation is when all of the codons are moved over

-Inversion is when a segment of DNA gets cut out and then reinserted backwards

-Translocation is when a segment of DNA is cut out and then inserted into a different chromosome

We will talk more about mutations during the next section on gene expression and see how they affect the organisms

Class Practice:

I will write some DNA code on the board, then I will rewrite that same DNA on the board but something will have changed. You have to say what type of mutation took place. This is how your quiz will be next class period.

Assignment:

Write a one to two page paper describing how DNA is replicated (total 20pts)

-First paragraph is an intro and background (3pts)

-Second paragraph describes the process (5pts)

-Third paragraph explains mutations and relates this info to what you previously learned about cancer (5pts)

-Fourth paragraph compares your new info to any previous misconceptions you might have had (5pts)

-Fifth paragraph will be your conclusion (2pts)

(The paragraphs do not have to be long but they do have to be informative)