November 30th

Luke Pilliod
11.30.10

Scribepost

Homework: UP pages 29-31

Today, Mr. Paek started off by giving candy to only some of the kids in class? After that he warned us of a potential pop quiz soon??

Then he started off the material of the day with a review on meiosis. Meiosis in simple terms is the creation of haploid cells. In diploid cells, homologous chromosomes duplicate before entering meiosis . The duplication of the homologous chromosomes forms sister chromatids of the original chromosomes, and the whole thing is called a tetrad. In the process of Meiosis I, the homologous chromosomes separate, with each pair of sister chromatids entering its own individual cell. In meiosis II, the sister chromatids separate, forming 4 new cells from the original cell. Here is another important piece of information he told us:

• 46 chromosomes in a regular cell, 23 in a sex cell

After the review there were some good questions in the class. One of these questions was "What determines a boy or girl?". A boy is determined when the sperm cell from the father has the Y chromosome, and a girl is made when the sperm has the X chromosome. So there is a 50/50 chance a baby will be a boy or girl. What is the Human Genome Project was another question. The Human Genome Project was a scientific mapping and identification of all the genes in the human body. This project has helped people benefit from information on what diseases they might be prone to.

Here are some terms we learned today as well

allele- form of a gene represented by a single letter

homozygous(Homo means alike or the same; zygous refers to the zygote and its genes)-a homozygote has two like genes for a given trait, AA, BB, zz, dd. The following are not homozygous because they are not alike

heterozygous(hetero-different)- a heterozygote has two different gene forms for a given trait

traits-hair, skin, eye color, blood types, bone structure, sex, height, shape of nose, eyes, immunity proteins in blood

phenotype- the result of a genotype in regards to it's functio or appearance. What a thing looks like

genotype-genes that give a phenotype

^Mr. Paek mentioned them and told us they were on page 21 of our UP, along with some more vocabulary

He further explained phenotypes and genotypes as well. A trait is represented by a letter, like B or b, B is the dominant trait while b is the recessive trait. These are the genotypes of the trait. The phenotype is the physical characteristic of the trait. In the trait hair color, B could represent black hair while b could represent brown hair. At the end of class, Mr. Paek told us of a trait where you either taste the bitterness of a certain type of paper or the paper tastes like regular paper. We all got a piece of the paper and although I did not get the gene for tasting the bitterness, I think most of the class did as I looked around at all the scrunched faces of disgust.

Next Scriber was josh