March 30

Today, Mr. Finley had us try to figure out what he wanted us to figure out why he asked us the homework questions after we went over it. We thought it was because some genes were recessive, as in they were in our parents but maybe didn't show up in them. Then they got passed down to us and we showed them. Mr. Finley asked the class who could make their tongue into a U, and almost everybody could. Then Mr. Finley said that we weren't exactly understanding the ideas of dominant and recessive genes, and he told us we would look at the pes again. We had to try to figure out the hypothesis that would allow us to predict the genetic combinations the children would have. Our hypothesis was that: To find the combinations of genes in the children, you need to combine the first gene with both genes in the second pea's genes.

March 29

Today, Mr. Finley announced we would get our tests back soon. The last person just took it. Then we started talking about growth. Mr. Finley had Rachel come up and compared them. Although they went through mostly the same processees, they were very different because they had different chromosomes. Then Mr. Finley made us do an activity on his website. We did the pea soup experiment. We had several pea plants with different combinations of chromosomes. We had to write down what we noticed about the peas and the simulation. Here's what I thought about the peas:

• Two parents


• Four children


• Both parents are brown


• Three children are brown


• One child is green


• Smooth and wrinkly textures


• Some parents and children are similar or identical


• They all have a combination of Y, y, R, and r chromosomes

This is what I noticed about the simulation:

• Use the radio buttons to mate two pea plants


• You can mate a plant with itself

Then we had to try and make a hypothesis that would allow us to correctly predict the kinds of peas that would be born when we breeded certain peas. My first hypothesis is that if you breed two plants with the same texture or color together, all the children will be the same texture and color. These were the results:

Parents: yellow smooth, yellow smooth

Children: Green smooth, yellow smooth, yellow smooth, yellow wrinkled

My next hypothesis was if there is at least one Y, it will be yellow. If there is at least one R, it will be smooth. If it's yy it is green, and if it's rr it will be wrinkled. Another hypothesis I had was that there will always be at least one exact copy of one of the parents among the children. These were both proven.

Parents: yy RR, yY Rr

Children: yy RR, yY Rr, yy RR, yY RR

We know now that all children will be made up of some combination of their parents' DNA. At the end of the period we figured out the hypothesis. Finley said we would talk about it the next day.

-LG Blog 4

3/28/11 Discussion on Meiosis

Today in class, Mr. Finley told us we were going to get our most previous test back as soon as the last person took their test. Talking about tests, we will have one, a week from tesday. Hopefully, before the end of the marking period(April 20) we will get back our lab reports.

Then, we continued off with our human example/simulation of meiosis which we left off on thursday(check thursday's blog if you are confused). We continued with prophaseII, in which the nucleur membrane disappears, chromosomes condense, and the two centrioles move to the opposite ends of the cell. After that, we decided to only focas on one cell because there were too many people. Then in metaphaseII the humans lined up on either side of the plate and the spindle fibers were attached to them. During anaphaseII, the people in the middle of the room (chromosomes) seperate (besty stage). Lastly, during telophaseII, the nucleur membranes reapear, forming four cells. We did not go over cytokinesesII because it was not neccasry, since everyone understood that the nucleaur membranes split...etc.

The more important discussion was when we started to take notes on reproduction! YAY! At first we talked about a single celled organism such as a peremecium cell and how it goes through mitosis to reproduce. We compared single cell reproduction to mutlicell reporduction, such as us humans. We said that the process of reproduction/meiosis starts off when two haploid cells( containing 50% DNA) such as an egg and a sperm cell, meet up in the same place at the same time. When the two cells join together, they form a zygote. After that, the zygote goes through mitosis to create more cells and to get bigger. The zygote starts to become into an infant. To add on, the infant goes through even more mitosis to become an adolescent. Especially during this time of a males life, around 12-17 years old, meiosis starts occuring in his testes. Keep in mind that mitosis is still hapening everywhere else in the body to repair and create more cells. Some key terms that you should know are that there are three different gametes(sex cells); eggs, sperm, and pollin. Continuing with the process of meiosis, when a adolecsent grows and becomes a man, he marries a woman and happily engages sexual intercourse. The purpose is to basically get the two halpoid cells in the same place at the same time. Once they meet and join they create a process called fertilization. Then the whole process of meiosis repeats. However, the main difference between a female going through meiosis than a male, is that she does it when she is in her stage of a zygote and an infant. Therefore, by now she would already be done with it.

I hope I have made you more clear on this topic that we learned today. If you have any questions, leave a comment and I will try my best to reply.

SK

#4 blog

Today we did an experiment directing and acting out meiosis. We have some people on tables acting as a cell membrane around the people who are inside acting as changing chromosomes. We are using string to symbolize spindle fibers. the string is attached to the chromosomes, that will pull apart the chromosomes. we used the people on the inside to made into chromosomes that then group into homologous pairs and we used the rest of the people on the inside are centriols. The homologous pairs are lined up along the equator in metaphase 1.The spindle fibers have attached to the homologous pairs.we acted out each step up to prophase and will continue on Monday. Above are example pictures of the simulation. See if you can identify what these stages are. "in comment"

Crossing over...

1)Crossing Over= two homologous pairs connect and exchange/switch a part of the homologous. Then a new cell is made.



2)Why are your siblings different from you?



You have different chromosomes because of crossing and everyone else because now we have different positives and negatives, so if everyone was exactly the same, only the same thing would be able to be contributed. This is called diversity.



Phases of Meiosis



1) Metaphase-Homologous chromosomes pair up and form tetrad



2) Anaphase I- Spindles Fibers move homologous chromosomes to oppisite sides



3)Cytokinsis II- Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed



4) Metaphase II- Chromosomes line up alomg equator, not in homologous pairs



5)Prophase I- Crossing over occurs



7)Anaphase II-Chromotids seperate

8) Metaphase I- Homologs line up alone equator.

9) Cytokinesis I- Cytoplasm divides, 2 daughter cells are formed.

R.R. #5

3-22-11-Today

First, we went over homework. The similarities and differences of meiosis and mitosis are:

Mitosis
metaphase 1 the actual chromosomes are lined up
100% of DNA at the end
asexual
2 cells are created
(diploid cells)
(skin cell)

Meiosis
more steps homologous pairs
exchange DNA
(called crossing)
(prophase 1)
metaphase 1
homologous pairs are lined up
50% of DNA at the end
sexual
4 haploid cells created
(gamete)
(pollen,sperm, egg)

Similarities
reproduction
both divide
DNA chromosomes similar stages
meiosis 2 is similar to mitosis
both deal with chromosomes not pairs

Then, we did a class demonstration, the homologous pairs line up, then trade DNA with eachother. They split into four different cells. One cell has all Will, another one has all Carter, another one has half Carter half Will, and another with half Will half Carter.

That was our discussion today.

This is my 4th time blogging
Lexi P8

March 18th, 2011 Carter Stumpf

First, to start of class we started discussing the homeowkr from last night. The homework was to anwser three questions on the website. The questions were 1. If egg and sperm cells merge how much chromosones will each one have? 2. How does this relate to homologous pairs of chromosones? and 3. Could we start with a normal cell, go through mitosis and get a sperm/egg cell? Why not?. A homologous pair of chromosones are a set of chromosones that represent the same traits. One chromosone comes from the sperm and the second one comes from the egg. Without one set of chromosones you could have disabilities. Sperm and egg cell combine to make the zygote. A normal cell can't go into mitosis and make a sperm cell because when it goes into mitosis the normal cell would want to make another copy of a normal cell not a sperm or egg cell so therefore it is not possible. The purpose of miosis is to only create a sperm or egg cell. Males only get miosis to start happening when they hit puberty and females are born with it completed. A stemcell is a cell that has deicided what it is going to be yet. Then, Mr. Finley passed out a handout talking about Meiosis. Eukaryotic cells can only reproduce asexually. Then the class ended with a suprise fire drill so therefore we had to finish reading the handout outside.