In case you are feeling motivated!

Merry Christmas Eve or Happy Holidays or Jolly Vacation!

I've been remiss in checking email over break and I found that several students were asking what they can be working on... such a motivated bunch!

When we get back to school we will be learning about gene regulation in prokaryotes.  You can find this information in the second half of Chapter 18.  We will then progress to gene expression in eukaryotes, which is described in all of Chapter 19.

If you are more interested in reading some of the topics we will be rushing through later in the year I advise you to look at the circulatory system, respiratory system, digestive system and development.  Unfortunately I don't have a book in front of me to see what chapters these are in, but there is a great section called the "Table of Contents" included in all newer textbooks :).

Enjoy the rest of your break and I will see you in the new year!

Mrs. Sutton

Mutations

Today's focus was on mutations to the DNA.  The two main categories for mutations are base-pair (or point) mutations and insertions/deletions.  Base pair substitutions may result in silent, missense or nonsense codons.  Insertions and deletions (unless they involve multiples of 3 nucleotides) result in a frameshift.  The impact of mutations depends upon the type and location of the mutation.  Several examples of genetic diseases based on missense mutations were discussed.  A few that were named were: sickle-cell anemia, cystic fibrosis and Tay-Sachs.  You can learn more about each of these genetic diseases, as well as others at http://www.ygyh.org/

Here are some great links about mutations:

• A very nice look at why a base-pair substitution may occur.
• http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter11/animation_quiz_3.html
• An explanation of deletions and insertions
• http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter11/animation_quiz_4.html 
• A focus on thymine dimers caused by UV light.
• http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter11/animation_quiz_5.html

Homework
Your homework tonight is to read pp. 359-361 and then take a look at the animations (there is also a good one in Ch. 19 of your textbook's website).  Then answer this one question: How does all of the DNA fit into the nucleus in an organized way?

http://www.pbs.org/wgbh/nova/genome/dna.html
http://www.biostudio.com/demo_freeman_dna_coiling.htm

Chapter 17 Quiz

Today we took a 17 question multiple choice quiz on Ch. 17 through 17.5.  I had 15 people absent!  See me as soon as possible to make up this quiz if you were excused absent today. 

I collected the Bioflix worksheet from last week for credit.

Homework is to read 17.7 on Mutations.