Thursday, February 25, 2010

Peppered Moths & Populations

Yesterday and today students took notes on populations as well as did an activity on microevolution and selection in peppered moths.

NOTE: there is one error in this clip. The narrator says "and so the moths began to evolve." What's wrong with this statement?

Homework: none

On Monday you will have a quiz on the packet.

We also had time for this National Geographic clip on adaptation in underwater creatures.

Tuesday, February 23, 2010

Methods of Evolution and a Case study

Today we talked about the methods of evolution (mutation, migration, natural selection and genetic drift)

In class we started to read a case study about the evolution of quiet crickets. The top photo is the normal cricket, the bottom photo is the cricket infested with maggots.

Homework: Finish reading the case study "Quick evolution leads to quiet crickets."Make sure look up the words you don't understand as well as write the key point in each paragraph.

Monday, February 22, 2010


What is evolution? What is not evolution?

Today we learned about Charles Darwin and other leading scientists who helped shape the theory of evolution.

Homework: Watch the video clip below and answer the questions in your packet. In case you have "misplaced" the packet, the questions are below the video as well.

Questions (which are adapted from the PBS teacher's website)
1. Below are four components of natural selection. Describe each of these components.

Genetic variation:

Overproduction of offspring:

Struggle for existence:

Differential survival and reproduction:

2. What kinds of limited resources can create a struggle between individuals in a population?

3. What kinds of variable traits within a population might natural selection act upon?

4. How does natural selection affect the genetic variation within the next generation of the same population?

Friday, February 12, 2010

DNA replication, transcription and translation projects

DNA Replication Poster

Yes, that IS marzipan DNA and RNA!

And that, my friends, is a translation pie.

Gel Electrophoresis

On Wednesday and Thursday we did Gel Electrophoresis using food coloring to see how molecules of different sizes move through the gel. The first step was to load the gels.
One all of the wells are loaded, an electrical current is run through the gel to move the molecules.

Voila! Results! Look closely and you can see that the black in the first well (on the bottom), has actually separated out into a purple and an orange. Blue is the largest molecule and therefore it moved the shortest distance. Gels were made with 2.5g agarose and 250mL 1x TAE buffer and run for ~ 20 minutes.

Tuesday, February 9, 2010

Gel Electrophoresis Homework

To prepare for lab this week go to the Virtual Gel Electrophoresis Lab and click through the animation.

You will have a prelab quiz, any notes you take, you can use for the quiz.

Monday, February 8, 2010

Genetically Modified Foods

How do you think scientists create genetically modified organisms? Even if you have no idea, write something down, THINK CREATIVELY!

2. We are going to watch an animation on Recombinant DNA technology. The questions that follow relate to this animation.

a. What is a vector?

b. What is a plasmid?

c. What are restriction enzymes?

d. What are the “sticky ends” of the gene segments? Use a drawing in your answer.

e. What is a transgenic plant?

3. What do you think are some of the benefits of transgenic organisms (T.O) (list at least 4)

4. What do you think are some of the controversies surrounding T.O.’s (list at least 4)

5. Video Monsanto: How does this make you feel about GMOs/TOs? Write at least 4 sentences.

Video India: How does this make you feel about GMOs/TOs? Write at least 4 sentences.

7. Video: The Future of Food Intro. What are three things you learned from this video clip?

Homework: Find an article on genetically modified foods. This article must be from 2007 to the present. Complete the article summary sheet.

Places to look for articles include:

Samples of Student work

Below are samples of some DNA replication, transcription and translation projects I have received in the past.

Friday, February 5, 2010

DNA replication, transcription and translation project.

Your project is due Friday February 12th, in class. You will be presenting your projects. This counts as a test grade. Click on the images below to see the rubric, each group will also get a copy of it on Monday, in class.

NOTE: This rubric has changed! The original rubric posted left off points for properly citing your sources. This is now part of the rubric.

Thursday, February 4, 2010

Transcription & Translation

Today we recapped DNA replication and started to learn about transcription and translation. Students took notes in their packets and we watched the video clip below. There's no homework tonight because of the International Food Fair.

Tuesday, February 2, 2010

DNA extraction

Today students extracted DNA from strawberries. Yvo, Claudia, Mariam and Finn had spectacular results.

After the lab, we started to learn about DNA replication. Tonight for homework complete the DNA replication worksheet using the online animation.

Click the picture below to link to the animation.

Monday, February 1, 2010

Intro to DNA

Today we talked about the structure and function of DNA as well as how Hershey and Chase determined that DNA, not protein, is the genetic material.

Click their picture to link to the animation we watched in class.

How small is DNA? Really small! Click here to view the slider we saw in class.

Homework: 1. Read the lab handout for tomorrow. You will have a short quiz on the procedure. Want to see the virtual DNA extraction lab? Click here.

Homework 2: Test corrections! For each question you got wrong, or lost points on, you need to rewrite the question and the correct answer on a separate sheet of paper.