Week of February 23-27

I was absent for Monday-Wednseday so not all of this might be accurate.
So this week we learned more about genetics. We can now somewhat predict what the eyes or hair might be. We use alleles that stand for the kinds of genes. There are three combinations of alleles. Two of them are used when we are talking about homozygotes (purebreeds) which are written like this BB or bb. With a heterzygotes (hybrid) it looks like this Bb. The uppercase letter is the dominant gene. The lowercase letter is representing the ressecive gene. For example if you're talking about right and left handed the right handed gene might be the dominant gene so it would be the uppercase letter. The left handed gene would then be the ressecive gene so it would be the lowercase letter. We also learned how to chart these to see what the off spring might be. I don't know how to put one of the squares on the blog so I can't show you. So everyone have a nice March.

week of February 9-13

This week we finalized meiosis and mitosis which I explained the process in my last blog. this week we started with genetics. On the computer we had asimulation that explained what happens with genetics when reproduction happens.
There was a monk who set the way we think about genetics. His name was Gregor Mendel. He did this by breeding his plants and using the theory that all living organisms inherit things from their parents. Each gene is called an allele. A plant with two alleles is called a homozygote. A plant with two different alleles is called a heterozygote. Also an offspring of two pink plants can have a white plant if both of the parents are heterozygote and both of the parent's white flower traits are passed down to the plant.

February 2-6

On Monday we learned about how diploid cells are 100% the same as their parent cell. These cells are made with mitosis which splits into two cells from the original cell. First the nucleaic membrane disintigrates. Then the cell goes through DNA replication. Then the DNA unwinds to make chromatins. Then the chromatins combine to make chromotids. Then The chromatids are joined together by a centromere to make a chromosome. They form an X shape. Meanwhile the centrioles start to form spindle fibers. The chromosomes go across the mitosis plain and the spindle fibers attach to the centrioles and pulls the chromosome apart back into chromatids except they are not chromatids anymore they are still chromosomes. Then the cell is pulled in two along with the chromosomes and a new nucleas is formed in both of the new cells. All of this occurs through several stages starting with interphase, prophase, prometaphase, metaphase anaphase, telophase, and cytokinesis. You would think that because the cell is split in two that each cell would only have 50% of the original DNA. But if you look back to the begining of mitosis the cell went through DNA replication which made twice the amount of DNA. So there is enough DNA to go around. Now we also learned that a haploid is a cell with 50% of DNA from the original. Which is produced through sexual reproduction. One process of sexual reproduction is Meiosis which we learned on Tuesday.
On Tuesday we learned about meiosis which is to produce haploid cells like sperm and egg cells. First just like mitosis the nucleaic membrane disapears and DNA replication occurs. Unlike mitosis when the chromatids make the chromosomes the chromosomes pair up into homologus pairs and the pairs crossover and take a peace of eachother. Meanwhile spindle fibers are being formed by the centrioles. The pairs aline along the metaphase plane and the spindle fibers attach to the pairs and pull them apart. Then the two daughter cells form just like in mitosis, but it doesn't stop there. It goes through interphase except there is no DNA replication. Spindle fibers form again and the chromosomes align along the metaphase plate and the spindle fibers pull them apart to make a total of 4 daughter cells.
On Wednsday and Thursday we recapped on it and learned that all of this occurs in stages called interphase, prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis, interphase 2, prophase 2, prometaphase 2, metaphase 2, anaphase 2, telophase 2, and cytokinesis.
On Friday we watched a simulation regarding all of the details at http://cellsalive.com/mitosis.htm.