Wednesday, December 17, 2008

Cracking the Code of Life

Today C block watched the NOVA special: Cracking the Code of Life. Click on the picture below to go to the website for the video.

Tuesday, December 16, 2008

Test Today

Today students had a test on Chapters 8 & 9. Several students scored 100% on the multiple choice. I will finish grading the tests tonight while I am on duty and if you are in D block you may email me tomorrow ( C block and A blocks can get their tests back in class) to find out your score.

Monday, December 15, 2008

Review for the test

Ok, I'll be the first admit it. Some classes had better review sessions than other classes. In case you missed it, here's the breakdown for the test:

25 Multiple choice questions (10 from chapter 8 and 15 from chapter 9). Each question is worth 2 points.

5 genetics problems, each question is worth 5 points.

Keep in mind there is a special schedule tomorrow because of the Pageant.
C block: 8:35-9:25
D block: 9:30-10:25
A block: 10:30-11:25 (This is your last class of 2008 A block!)

Saturday, December 13, 2008

Do you know what you're eating?

We've come a long way from Mendel, in the 1860's, tinkering with in his garden with Pea Plants. Instead of removing stamens from one flower and transferring that pollen to another flower, scientists can now insert genes into plasmids and create GMO's (genetically modified organisms).

"Today, four countries account for 99% of the world's commercially grown transgenic crops. But that is changing — policies are being thrashed out, laws drawn up, and seeds sown. Here we show how GM is taking root. Click on the map for information on the big hitters in the global GM scene."~ From

What do you know about GMO's? Click start quiz below to take a quiz!Now that you've tested your knowledge, watch the videos below in for and against GMOs. Continue to ask questions and form your own opinion.

For GMO's: Click here to be taken to videos produced by Monsanto. Each clip is 2-3 minutes long.

Watch the video below that is against GMO's.

Friday, December 12, 2008

Wrapping up Chapter 9

Today and tomorrow we will be finishing chapter 9 by learning about pleiotropy, polygenic inheritance, chromosome mapping, sex determination and sex linked genes (sections 9.14-9.22).
Your book doesn't talk about Environmental Sex Determination (ESD) and this stuff is actually quite interesting. "The sex of hatchling turtles, like this Barbour's map turtle, is determined by incubation temperatures in the nest. Relatively warm incubation temperatures produce females, whereas cool temperatures produce males. Barbour's map turtle is only found in the Apalachicola River and its major tributaries in Alabama, Georgia, and Florida." To read the rest of the article click here to learn more about ESD and Climate Change.

Homework: Finish the remainder to the practice problems (through question 10) on the Genetics Practice Problem Sheet.

Tuesday, December 9, 2008

Genetics Problems for Lab on Wednesday & Saturday

For this week's lab you will be acting as Mendel would have in the middle of the 19th century. Go through each of the slides below (you can click on the picture to make it larger). For the first 15-20 minutes of class you are OWN YOUR OWN, you may ask your peers and work together, I will only answer minimal questions. Write your answers on sheet of paper.

This lab activity was developed by Dr. John Crosby for ASP.

Classical Genetics

Today students turned in their projects on meiosis and non-disjunction disorders. Today students learned how to solve trihybrid crosses using the multiplication rule.

What is the probability that AaBbCc X AaBbCc will produce an individual that is homozygous reccessive?

One option for solving a trihybrid cross is to make a giant punnett square (see below) or you can the multiplication rule.

Using the multiplication rule you take the probabilities of each individual event and multiply them together. There is a 1/4 chance of aa, 1/4 of bb and 1/4 chance of cc, multiplied together this equals 1/64.

Click here for practice genetics problems.

Monday, December 8, 2008

Jonah Lehrer Talk

Tonight at 6:15 is Jonah Lehrer's talk in Hargate. There are two ways to earn extra credit. One, raise your hand and ASK a question. Two, post a comment on this post answering the following questions. You must write in complete sentances and you must post before 10:00pm this evening.

What are 3 things you learned from this talk, BE SPECIFIC!
What are 2 things you want to learn more about, BE SPECIFIC!
What is one question you would like to ask Mr. Lehrer.

Patterns of Inheritance

Today we started chapter 9 and we're going to try something different. Rather than just using a PowerPoint and having students take notes, I created a packet that is a notes outline for chapter 9 with practice problems for most concepts. Over the next few days we'll work through the packet and only use PowerPoint to show diagrams that are too complex to draw on the board.

Here are the topics/concepts we went over today:
* Alleles, loci & homologous chromosomes
* genotype vs. phenotype
* homozygous vs. heterozgous
* Mendel's principles of segregation and independent assortment
* Test crosses & how to do them
* Interpreting family pedigrees

Reminder: your meiosis project is due tomorrow.

Friday, December 5, 2008

Nondisjunction Disorders

What happens when (as your book says) there's an "accident" in meiosis. One of result is that there could be a nondisjunction disorder, where sister chromatids do not separate evenly. Today in C block and tomorrow for A and D blocks we will wrap up chapter 8 by talking about variation and nondisjunction. Click the picture below to learn more about chromosome abnormalites from Utah Genetics. Remember, as part of your meiosis project you need to incorporate a nondisjunction disorder.

Thursday, December 4, 2008

Extra Credit Opportunity...

....also known as an outright bribe to attend Jonah Lehrer's talk on Monday, December 8th at 6:15 in the Hargate Auditorium.

There are two ways to earn extra credit through this talk. The first is to attend the talk and ASK a question (just raising your hand doesn't count, you need to ask the question). The second is to attend the talk and then before 10:00pm on Monday December 8th, write a 3-2-1 comment using complete sentences on the blog. I will create a post for the talk on Monday.

Wednesday, December 3, 2008

Down Syndrome

As women age, the risk of Down Syndrome can increase (see graph below). Click the graph to be taken to the article.

However, a 2006 study shed new light on the causes of Down Syndrome. "Neuhäuser and Krackow reviewed and analysed data from 1953 and 1972 (before abortion was widespread). They found that other factors, besides the mother’s increasing age, were linked to the number of Down Syndrome cases. Down Syndrome rates were significantly higher in older mothers in their first pregnancy than in older mothers who had already had children. Only late first pregnancies were more likely to produce a Down Syndrome baby, not late second or third pregnancies. In addition, the larger the gap between pregnancies, the higher the rates of Down Syndrome." Click here to read the full article on Science


Today (and Thursday for A block and Friday for D block) we talked about Meiosis and how it compares to Mitosis. Students took notes and the worked with a partner to complete a short packet of questions.
For more practice, try the Meiosis Tutorial from the Biology Project. See the diagram below for a comparison between mitosis & meiosis. You can click on the picture to make it larger.

Tuesday, December 2, 2008

Welcome Back!

Welcome to winter term! Today during block classes students completed a fall term course evaluation. Students were also given their invitations to present at the 2008 Intergalatic Planetary Conference for Biologists (a short project due Dec. 8th).

Students were also given an open notes/open book take home quiz due the next class period. What is the point of an open notes/book quiz? The goal is to get students review and practice with multiple choice questions.

Monday, December 1, 2008

World AIDS Day

Today is World AIDS Day. According to the CDC, "December 1 is World AIDS Day; a time to celebrate the many lives saved by HIV prevention and treatment programs. It also serves as a reminder that we all must do more—as individuals, communities, and as world citizens—to fight the spread of HIV and AIDS."

Every 12 seconds another person contracts HIV. Want to learn more about the number of people affect by the virus and where they are from? Check out the interactive AIDS Clock.