Wed. March 23

My 1st blog was deleted so i had to start over :(! Today, was s a short period! in class, we talked about crossing over from yesterday. Crossing over is when the chrosomones spilt and take half a piece of each other. in prohase 1, your homlegous pair you connect to them and form a tetard. the picture about crossing over druring meiosis is shwoing how the homlogous pairs changes during each of the stages. Mr. Finley also told us that ><. then he told us to stand on our chairs and he told us if you had brown eyes you died, which is why he asked if you had brown eyes, why did the population decrease? it decrease because most of the students had brown eyes in the class. we went over our homwork and we went to lunch!

-Jodi Bull (4th round) :)

Mitosis and Meiosis

Today in class we talked about the similarities and differences between the process of mitosis and meiosis.

Mitosis
-trying to split chromosomes
-end up with 2 cells
-cells are body cells
-asexual
-body cell-growth and repair

Meiosis
-more steps
-meiosis1 spindle fibers connect to one side of chromosome
-happens because we're splitting homologus pairs
-end up with 4 cells
-cells are gametes
-gametes {sex cells}
-sexual
-2 divisions which gets you 4 cells
-crossing over occurs between homologus pairs

Similarities
-DNA and chromosomes
- meiosis 2 is similar to mitosis {splits chromosomes}
- cell division
-utilize centreols
-envolve eukaryotes
-X shaped chromosomes

Notes

-The point of meiosis is to make a new sperm and egg.
-Girls finish meiosis before we are born and don't go through it again
-Meiosis is in the overes
-For boys it starts at 10-13 and they go through it until they are about 70
-It's in the testies for boys
-Meiosis can happen without having a child present

Crossing Over

Crossing Over is when 2 chromosomes split and take a piece of each other (about a quater) the homologus pairs connect and form a tetrad.This happens in prophase 1. A tetrad is a group of chromotids.

-Allie Mansfield 4th time<3

Mr. Finley's class blog- 3-18-11

Egg cell....................................

sperm cell....................................

Happy friday everyone!!!! Tonights the dance!!!! (just reminding everyone, lol). So now onto science. Our homework was to read the questions on mr. finleys homework page and then write the answer in our notebooks or on the computer. These were the questions:

1. If an egg and sperm cell merge, what can you say about the amount of chromosomes each must have?
It must be 50% percent of chromosomes from each cell (egg and sperm) when they merge so that the daughter cell can have 100% of their chromosomes.

2. How does this relate to a homologous pair of chromosomes? (same kind)
Sara attemped but failed at the answer. It's ok, Sara! she said that half come from the mom and half from the dad chromosomes, but Mr. finley objected. Homologous pairs pair by 2's. He explained this on the board. HALF of your homologous pair comes from the mom (chromosomes), HALF of your homologous pair comes from the dad. Good save, Sara! Once again, a homologous pair is two chromosomes that have the same trait. Chromosomes determine how you look, like your physical traits.

3. Could we start with a normal cell, go through mitosis, and end up with an egg or sperm cell? why not?
No this is not possible. You cannot just get a skin cell to produce a egg cell out of nowhere. Plus, cells can only produce cells that are the same kind as them. When we split two skin cells, we need them to have 100% percent of chromosomes for the two new daughter cells to have 100% of the chromosomes as well. But when we have a sperm and egg cell, we need them to have 50% so when they merge, they will create 100% percent for the new cell.

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After this, we began reading an article on meiosis. It talked about how flowers are still producing sexually because they self-pollinate and also how diferent mammals and plants reproduce asexually and sexually. Some key terms are:

Haploid- Repeoductive cells containing half of a parent'c chromosomes.

Zygote- Combined sperm and egg cell

Fertilization- process of sperm fertilization of the cell

By the way, Mr. finley added that sexual reproduction and sexual intercoarse are NOT the same thing. (awkward, yes, but nessicary!!)

Now today, (monday) mr finley is away and now we are working on a venn diagram and also a meiosis activity. See you tomorrow Mr. Finley!!!!!!!!!!!!!!!!!!!

That's all!!!!

- Caroline S. (best student ever) :D
- caroline s :D

3/17/11

The Cell Cycle

First in class, Mr. Finley told us that if we couldn't do the homework from last night because your computers wouldn't open the simulation, you can show him the homework tomorrow. Also, if you can't open the simulation, it works better on older computers.

Paramecium

Next, we discussed with our groups about how a paramecium reproduces. My group said that a paramecium is single-celled and eukaryotic, so the paramecium would go through mitosis. First, there is prophase, which is when chromatin becomes chromosomes and becomes visible, the nuclear membrane breaks down and dissolves, centrosomes become centrials which also move to opposite sides of the cell. Next, there is metaphase. Metaphase is when the centrials create spindlefibers which align the chromosomes at the center of the cell. Then, anaphase is when spindlefibers pull chromosomes to opposite sides of the cell. Lastly, telophase is when a new nucleus forms around chromosomes and the cell starts to pinch closed.

Next, we discussed how we reproduce. We need two parents and the offspring don't look exactly like the parent because it has genetic information from both parents. Also, sexual reproduction and sexual intercourse are commonly mixed up. Remember that sexual reproduction is the actual cells reproducing.

We also learned that....
-sex is just a delivery method that gets the cells where they need to be

-sperm cell- male

-egg cell- female
-other traveling cells are pollen (plants) and spores (fungus)

-sperm cells come from testicles

-egg cells come from ovaries

-zygote- combined cell

When the sperm cell finds the egg, the genetic material combines, it becomes one cell , and the cell continues to grow. When the cell combines, the new cell has 50% of each original cells chromosomes (50+50= 100%).

M.K.B. 4th blog

Today in Mr. Finley's class we finished the rest of the slide shows that are getting graded. After we finished the slide shows, we went over our homework from last we about the two animation videos about mitosis and we had to write a paragraph of which video is better to explain mitosis. we also went over our class work from yesterday.








Questions and answers from school work yesterday.



1. How does binary fizzen relate to cell division?

A: it is a form of asexual reproduction occurring in prokaryotic


3.compare sexual reproduction and asexual reproduction

A: asexual reproduction you look exactly like your parent
in sexual reproduction you look some what like your parents. we don't reproduce asexual reproduction we are sexual reproduction.

these are the only two questions that you need to know.

Importent info about chromosomes

• these are called autosomes which are also chromosomes


• chromosomes go from two lines to an X shape


• l l - sex chromosomes


• when chromosomes are in X shape there special term is called chromotaids - only called this when its in X shape
• chromosome are always in a pair even when there in X form

Reproduction in cell Division

Today in class we are reading pages 88 to 92. We have to answer questions 1 through 6 on page 92.

1) Binary fission relates to cell division because they both reproduce cells.

2) A bud is a process in which an organism develops tiny buds on its body. The buds are formed by the parent cell. This means that the buds genetics are the same as the parent cells genetics.

3) Asexual Reproduction: Sexual Reproduction:
Cell division Cell division and other process
One parent organism Two parent organisms
Rate of reproduction is rapid Rate of reproduction is slower
Offsppring identical to parent Same genetic info as parents






4) No, prokaryotes can not got go through regeneration because they are only single celled and if they are single celled, they will because mitosis die and they can not repair themselves when they are not alive.

5) Binary fission is like mitosis because it has a cell splits and makes new form of itself. The daughter cell is like the parent cell. They are different because mitosis only happens in eukaryotic cells.

6)They have traits there parents dont and vice versa.

Garrett Pope 4th Blog.

in the beginning of class we went on the computers and we started working on our presentations.
Our presentations are about the cell cycle including these parts:
-Interphase (growth, DNA replication, and preperation for cell division)
-Prophase
-Mataphase
-Anophase
-Telophase

On friday we took pictures with our phones after we organized what the cell looks like in each phase, and now we are writing about what happens in each phase.

in INTERPHASE, the DNA duplicates to prepare for mitosis. in interphase the nucleus isnt completely visible.

in PROPHASE, the nuclear membrane dissolves so that you cant see it anymore. the chromotin becomes chromosomes. the centrosome becomes 2 centrials and they move to opposite sides of the cell.

in MEAPHASE, the centromere is connected to the centrials by spindle fibers. the spindle fibers align chromosomes inside the cell.

in ANAPHASE, the paired chromosomes seperate at the kinetochores and move to opposite sides of the cell.

in TELAPHASE, the new membranes form around the daughter nulcei while the chromosomes disperse are not vivible inside the light of the microscope. Cytokenisis can also begin during this stage.

Chromosomes: coiled DNA

Chromatin: uncoiled DNA

ALYSSE MACHALEK (BLOG 4)