Chi what?

[caption id="attachment_949" align="alignleft" width="300"] By Kid's Birthday Parties[/caption]

Can't believe it, but the first 9 weeks have come and gone. One quarter of the school year is complete. Honestly, I've had a blast with AP Bio so far. After teaching it is nice to teach a classroom full of curious students who are diligent about completing work and enjoy learning just for the sake of learning. Don't get me wrong, I love teaching freshmen. It's just a completely different ball game. 

With the new quarter comes a new round of the week in review. The second quarter opening with the conclusion of our unit on genetics and a tasty introduction to the statistical world of Chi square analysis. This week's installment of the week in review (10/8-10/12) is brought to you by Justin Quimbo and Asia Johnson.

Justin Begins:

On Monday of this week, we constructed pedigree charts and answered questions along with one other person. The charts weren’t all that confusing at first but as the worksheet went on and described the rest of the families, it got a lot harder keeping up with who was a carrier, who had the disease, and who didn’t have it. I think the point of this work was to show up tough geneticists jobs are.

Later that week, we learned about Thomas Hunt Morgan and how important his experiments on flies were to describing sex linked inheritance. We also learned about the importance of chi-square. Chi-square is used to compare expected and actual data. It gives you a range of numbers to look at depending on your degrees of freedom. If you’re numbers fell in the range of that data, then your data was valid. Our activity for chi-square was comparing the number of each color of M&M’s you had to the number other groups had, and eventually comparing the class set to the numbers the official M&M website gave us.

Finally we ended the week off by watching videos about sex-linked genes and linked genes. The sex-linked genes video talked about disorders and the function of the SRY gene, which is the instructions in the Y chromosome for testes, testosterone and anything else needed for a male. The linked genes video also talked about disorders but most of the video was directed to Thomas Hunt Morgan’s fruit fly experiment and linkage maps that map out the location of genes on a chromosome.

Asia Concludes:

After a nice long 3 day weekend which marked the end of the 1st nine weeks, AP Biology students came back ready to dive in to the next piece of information. After looking through my spiral notebook, I’m glad to say that I have actually filled up a whole notebook, what an accomplishment for me!! Anywho, back to Biology this week we did alot of reviewing for our Genetics test, (10/18). On Monday we reviewed complex inheritance which basically talked about the difference between dominant and recessive alleles. A dominant allele is one that produces more of the trait than a recessive one. There are 2 different types of dominance including incomplete…Mr Kite’s example was if you crossed a white flower(W) with a red flower(R) you would receive a flower that turns out pink. Whereas in codominance…if you crossed the same two flowers you would get a result of a flower showing a phenotype of both white and red petals (odd right?) A very common example of something with multiple alleles is blood type (A, B & O). Alot of new vocabulary was also introduced in this section. We also dug wayyy back in our minds to remember learning about pedigrees, which seemed to come easily to everyone because we have been taught it many times before. In a pedigree a male is a square (hah…be there or be square) and a circle represents a woman(and all her curves), just the easiest way for me to remember. Some dominant disorders include Cystic Fibrosis and Sickle Cell Disease…whereas some recessive disorders include Achondroplasia(dwarfism) and Huntington’s disease. After we reviewed about pedigrees, we completed a case study about Olga and Greg, two people with histories of diseases wanting to have children. Wednesday we were introduced to something known as a Chi square to use statistics to compare actual and expected data by using a mini M&M lab to determine the difference between our o(observed actual data) & e(statistically expected data). Thursday and Friday we talked about Linked genes and Sex Linked Genes and completed a mini lab on Sodaria. This lab isn’t easy to explain in words, but it was very interesting to complete. We also completed another assignment on the Sex Linked Disease of Hemophilia within the royal family in Russia known as the Romanovs.


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