Mutations continued

Today we finished up the notes on mutations and watched a clip about a specific mutation that causes Polydactylism (having extra fingers/toes)  we started the class off with the following daily questions

Wednesday May 2nd

**True or False: Mutations = ALWAYS BAD…… FALSE!!! A mutation does not ALWAYS mean something bad will occur.  Mutations can be adventagous at times, they can be harmful or they may simple have no affect at all on a characteristic.  The term mutation simple means there is a change in genetic material.... The end!!!!**Which statement is true regarding an alteration or change in DNA?
    A.  It is always known as a mutation
    B.  It is always advantageous to an individual
    C.  It is always passed on to offspring

**A mutation occurs in a cell.  Which sequence best represents the correct order of events involved for this mutation to affect the traits expressed by this cell?
A.  Change in DNA bases → Change in amino acid sequence → change in appearance of characteristic
B.  Change in amino acids → change in DNA bases → Change in characteristic
C.  Change in characteristic → change in amino acids → change in DNA bases
D.  Change in DNA bases → change in characteristic → Change in amino acids

**True of False:  DNA that is mutated in our lifetime in somatic cells will be passed on to our offspring. FALSE!!!  Only DNA inn our germ line cells (those that will go through meiosis and become our gametes) will be passed on to our offspring.  Mutations that occur in our somatic cells DURING our life will not be passed on.

**Which of the following types of mutations would have the greatest affect on the protein that the gene codes for?   Missense, Silent or nonsense?
Nonsense:  A nonsense mutation causes a premature stop codon - so the rest of the amino acid chain will not even be made.  Missense can still have a large affect on the protein, but in general we would probably see the biggest affect with a nonsense mutation.
After the daily questions and finishing the notes on mutations I had you watch the following clip.  We talked about the trait for 6 fingers when we learned about heredity.  If you recall I mentioned that having 6 fingers was actually a dominant trait.  What that means is in order to have a child with 6 fingers, one of the parents HAD to have had Six fingers.  In this case the father did, but as with most people who are born with an extra didget - it was removed as a child.  The odd thing about this case is that the baby has a fully functional 6th finger AND 6th toe.  This now brings into our discussion on gene expression.  Rememer, when and how genes are expressed is VERY complex.  Obviously this little boy is fully expressing the gene in both his hands and feet.  His father, on the other hand, may have only been expressing the gene "slightly" in his hands and not at all in his feet.