Spermatogenesis and Oogenesis

Click here to view an animation about spermatogenesis. Take the quiz at the end. How did you do?

Click here to view an animation about oogenesis.

Meiosis

Click here to view a detailed animation about meiosis.

Click here to view an animation that describes nondisjunction. Nondisjunction occurs when there is a mistake during mitosis or meiosis. What happens to the cells that are made through nondisjunction?

More meiosis animations here and here.

Cancer - Uncontrolled Mitosis

Cancer is any malignant growth or tumor caused by abnormal and uncontrolled cell division; it may spread to other parts of the body through the lymphatic system or the blood stream.

Click on animation 1 to see how cancer occurs in body cells.

Click here for a more advanced explanation.

 

This week in current events

All Black Penguin Discovered

The World's Only Immortal Animal

Tuna, Polar Bear Protection Rejected

How does each article relate to Living Environment Curriculum? Explain?

Which article was your favorite?

**Special thanks to Michael Nguy!**

Mitosis Animation

Click here for a narrated animation of mitosis. Take the quiz when you are finished. How did you do?

Do you want to view the animations we watched during class? Click here to view the animation by CELLS alive and here to view the second animation.

Enjoy!

Karyotyping Activity

Click here to complete a karyotype for 4 different patients. Click on, "patient histories," at the bottom of the page to access their chromosomes.

What did you learn about each patient?

Click and Clone a Mouse

Click here to click and clone Mimi. This is the same animation we used in class.

Do you support cloning animals? Is it ethical? Why or why not?

Science Summer Camp

Are you interested in attending Science Summer Camp 2010?  Click here for more details about the exciting programs that are offered.

Online application

Let me know if anyone decides to sign up - it looks like it will be a lot of fun:)

 

Restriction Enzyme Animation

Click here for an animation that explains how restriction enzymes cut DNA.

Still confused? Think of it this way: our bodies naturally produce restriction enzymes. We call them digestive enzymes, like amylase, trypsin, pepsin, protease, lipase, etc. These enzymes are not effective to cut DNA for genetic engineering purposes because they cut DNA randomly. That's why scientists rely on restriction enzymes produced by bacteria. These enzymes can cut DNA at precise locations.

A restriction enzyme recognizes and cuts DNA only at a particular sequence of nucleotides. For example, the bacterium Hemophilus aegypticus produces an enzyme named HaeIII that cuts DNA wherever it encounters the sequence

5'GGCC3'
3'CCGG5'

The cut is made between the adjacent G and C. HaeIII cuts straight across the double helix producing "blunt" ends. However, many restriction enzymes cut in an offset manner (like HIND III that we used during the gene splicing simulation). The ends of the cut have an overhanging piece of single-stranded DNA. These are called "sticky ends" because they are able to form base pairs with any DNA molecule that contains the complementary sticky end. Any other source of DNA treated with the same enzyme will produce the same cuts.

Mixed together, these molecules can join with each other by base pairing between their sticky ends. The two DNA molecules can be joined by another enzyme, DNA ligase. The result is a molecule of recombinant DNA (rDNA).

The ability to produce recombinant DNA molecules has allowed geneticists to produce human insulin (for diabetics), human factor VIII (for males with hemophilia A), and other proteins used in human therapy all were made possible by recombinant DNA.

Gel Electrophoresis

Click here to view an animation of gel electrophoresis.

Selective Breeding

Click here to practice your selective breeding skills. Can you create the largest crop of corn? Try it!

Mutations

Click here to view an animation that explains how mutations occur in your DNA.

Click here to view an animation about sickle cell anemia, a genetic disease caused by a mutation in the hemoglobin gene.

Click here to view an animation that explains how a drug, Gleevec, can stop the harmful effects of a specific type of Leukemia.

Click here to read an article about the genetic cause of a rare bleeding disorder. Special thanks to Maya Shaar!