Punnett Square

Throughout the topic of genetics in science class, we have been learning about and using the Punnett Square. The Punnett Square is a type of grid, in the topic of genetics, used to show the gametes of each parent and their possible offspring, or a type of grid that can indicate all the possible outcomes of a genetic cross; also called [checkerboard]. We have done various experiments and activities that involve using Punnett Squares, such as Hamster Vacation, the Super Hero project, Toothpick Fish Activity, and various coin flipping activities. To see a Punnett Square, click the link below:

http://www.geocities.com/geneinfo/graphics/dominant.jpg

Throughout the genetics topic, I have learned that Punnett Squares show all of the possible combinations of alleles, that a Punnett Square is used like a multiplication table, and that a capital letter on the Punnett Square will always represent the dominant gene, and the lower case letter on the Punnett Square will always represent the recessive gene. I believe that knowing how to read a Punnett Square is very important and useful because it is a quick and simple way to figure out a child's allele possibilities and can be used throughout life. To learn how to use a Punnett Square, follow the steps below:

Steps to Using a Punnett Square-

1. Draw a box that is two blocks by two blocks

2. Label one of the dominant allele combination's alleles in each of the boxes across the top.

3. Label one of the recessive allele combination's alleles in each of the boxes along the right-hand side

4. Use the Punnett Square like a multiplication table
(dominant allele comes before recessive)

5. Determine the outcome by counting the number of new dominant and recessive allele pairs

Exotic Creatures Found After Melting of Ice Shelves in Antarctica

After ice shelves near Antarctica collapsed due to what appears to be Global Warming, scientists have been able to observe the exotic marine life below the surface earlier this week. These crumbling ice shelves are not expected to directly cause rising seas, but since the ice shelves act like damns to slow down glaciers, without them, the glaciers may move more quickly, substantially causing rising sea levels. Although the melting ice shelves are causing a sense of worry, this event also let scientists a great opportuninty to see the unique and exciting life under the surface, which used to only be seen through holes in the thick ice. The scientists found creatures at a depth of 2,800 feet that would normally only be found in water almost three times as deep. Gauthier Chapelle and other scientists found 15 possible new species of amphipods, and four possible new species of cnidarians. Orange sea stars, fan-finned ice fish, sea cucumbers, sea squirts, and blue ice fish were among the hundreds of of speciments collected. The discovered specimens will be examined to determine whether or not they truly are newly discovered. http://www.cnn.com/2007/TECH/science/02/25/antarctica.icecreatures.reut/index.html

BEAVERS!!

Earlier tis week, a twig-and-mud lodge was spotted on te Bronx River's bank, indicating that a beaver was living there. Then on Wednesday, February 21, a beaver was actually videotaped swimming up the river by Biologists. This may seem normal ad insignificant, but beavers hve not been present in the city for more that 200 years when they had disappeared because of trappers in the early 1800's. Now that that the beaver population is expanding and there is less room for habitats, more beavers are expected to be seen, says beaver expert Dietland Muller-Schwarze. The beaver that has been seen is thought to be a male, about 2 or 3 years old, and several feet long, says Patrick Thomas, from the Bronx Zoo. The animal was nicknamed "Jose", in honor of Jose Serrano, a U.S. Representative who worked to clean up the river. It is predicted that "Jose" is the first of many beavers soon to venture back to the Bronx.
http://www.cnn.com/2007/US/02/23/beaver.bronx.ap/index.html

electronic light boards shut down most of Boston

Last Wednesday, January 31, electronic light boards advertising the late-night Adult Swim cartoon "Aqua Teen Hunger Force" were mistaken for bombs in the city of Boston. These advertisements depicted light up moon-men that blinked, and were placed throughout the city. Once these advertisements were noticed by police, most of the city was evacuated and bridges were closed down, causing a major disruption. Police and prosecutors blame Turner Broadcasting for not taking the proper steps to stop the confusion and for not apologizing properly. Compared to police and prosecutors, some citizens disagree with arrests made and say that the situation may be taken way to seiously.


http://www.cnn.com/2007/US/01/31/boston.bombscare/index.html

DNA Structure

On Wednesday, January 31, 2007, Mrs. Rousseau's blue science class built the DNA structure out of toothpicks, gummy bears, chocolate and strawberry licorice, and string. We used green gummy bears to represent Guanine, yellow for Cytosine, orange for Thymine, and red for Adenine. The chocolate licorice represented Phosphate. We learned that Cytosine only goes with Guanine, and Adenine only goes with Thymine. During class, we also learned that the DNA structure is called a Double Helix. I learned from http://www.accessexcellence.org/RC/VL/GG/structure.html that Adenine and thymine are connected by two hydrogen bonds and guanine and cytosine are connected by three. I also learned that there are 4 different bases in a DNA molecule: adenine (a purine), cytosine (a pyrimidine), guanine (a purine), and thymine (a pyrimidine). This piece of information was from http://www.accessexcellence.org/AE/AEC/CC/DNA_structure.html. I definitely think that this was such a great way to learn about the structure of DNA because since we used candy to build it, the class was definitely more interested. Also, I really enjoyed the hands-on activity and thought that we learned more by actually building the structure. To sum it up, I learned a lot from building the DNA structure and also had fun while doing it.