What do you think about it right now? I'd say it's the cell division concerning sexual reproduction.
Now that's gotta hold your attention. First and formost, you guys need to know what gametes are. So...
1)What are Gametes?
They are the little things you call the sperm from a male and the egg from a female. "Gamete" is just a fancy, general word for them. As you probably know, a male and a female "do the dirty" if you know what I mean. I mean if they really didn't want to have a kid, then they could have just used contraception for goodness sakes. But, surprisingly some people do want kids, and reproduce.
That is what the gametes are for - to go on to create zygotes (which was already explained in the "Mitosis" part of this series) which go on to mitosis and grow into a fetus, mitosis, then finally "popping out" as a baby. Of course mitosis happens almost all the time when regenerating new body cells but I won't go into that again. This article is about MEIOSIS.
In a nutshell, a zygote is pretty much the product of a sperm and an egg. The thing that is entirely different from Mitosis is that the chromosome numbers change throughout.
2)Chromosome Number Changes
Let's try to make this seem as simple as possible.
*All organisms start of as a zygote, with 46 chromosomes in each cell
*They go through mitosis (cell division for growth) for a particularly long period of time I expect and then become an adult. w00t! Legal! Now they will still hold the same amount as before - 46 chromosomes in each cell
*Now is when the numbers go all haywire. In each gamete, there would only be 23 chromosomes. The process in creating these 23 chromosome in each sex cell would obviously be meiosis
*Through fertilisation, the male's sperm would reach the female's egg and then eventually create what you all call a zygote.
*The two gametes together would make 46 chromosomes again, 23 from each parent depicting different randomised characteristics.
*The 46 chromosomes would accord to the zygote
*So then mitosis would occur, hence the child would still have 46 chromosomes in each body cell.
*The child grows up to be an adult... and you get the idea. The process would go on.
3)What is Meiosis anyways?
Meiosis is a little harder to explain than Mitosis was but I'll try my "very very best" to help you all. Besides, I have my trusty Science Workbook to help me through this study, as you call it. Writing articles seems to be more interesting than reading over the same damned notes over and over again. I suggest you try writing down your own articles to help yourself understand the content better, but if you're much too lazy, I guess you'll just have to read my article. *Oh dear*
Meiosis is basically the cell division process which helps to make gametes [sex cells] from ordiinary 46-chromosome cells. It is the process that is vital in sexual reproduction.
If it didn't exist, we wouldn't be here. The animals wouldn't be here. Even the plants wouldn't be here. Don't you see the importance of meiosis. I guess it would be impossible for it not to exist since we are here in this instance. Just shut me up. I'm talking shit again.
4)Basic Facts about Meiosis
*Meiosis only occurs in the sexual organs of an organisms
*It results of making sex cells called gametes
*Four daughter cells are produced
*Each of the cells produced are entirely unique and have a different genetic make up
*This increases the genetic variation and improves a species survival
*Each cell produced from this cell division would have half the set of chromosomes of their parents (eg. a human has 46 chromosomes in a cell so the daughter cells from meiosis would count up 23 chromosomes
What really does happen in the process of Meiosis? Hmm... well be prepared for some deja vu because some parts of the meiosis process are similar to that of the Mitosis process. I say similar, because they are not exactly the same.
NB. If you are a little stupid (like me x_x) chromosomes are lengthwise, not little blobs!
*First of all, there are cells, right? And in the cells are chromosomes. The example I will use here would be a cell with 2 pairs of chromosomes. Let's call them homologous.
Homologous means two pairs with the same type of chromosomes in each.
*In the centre of each chromosome is a centrometre which is obviously at the centre of the cell. The chromosomes are duplicated but still remain attached at the centrometre.
*Spindle fibres from each "pole" of the cell attach to the centrometres and the chromosomes line up in homologous pairs in the centre of the cell.
*The spindle fibres attached from each pole become a little shorter and seperate the homologous pairs, so there's one type of chromosome on each side of the cell.
*The spindle fibres disappear and the cell forms a waistlike formation and splits into two seperate cells.
*In their new seperate cells, the spindle fibres recreate and the chromosomes are lined up in the centre of the cells.
*The spindle fibres get shorter and pull each chromosome apart so the chromatids move to the opposite ends of the cells.
*The cells again form a waistlike structure and then would finally split into a total of four daughter cells altogether.
Phew. Now, aren't I exhausted? I hope that you understand my explanation - even just a little bit, because I kind of understand it a little more too.
Maybe you would like to remember the process a little better without having to recite the whole sentences I provided. Here's a quick and easy note guide.
*Line up in homologous
*Chromosomes to centre
*Chromatids to poles
6)Extra Know-how stuff
During meiosis, when the homologous pairs are lined up in the centre, the paired chromosomes kinda "wrap" around each other and swap little tiny chunks of genes, like sending and swapping emails, or any other comparison you could make. In human, there would be about ten crossovers per chromosome. Imagine that? That mean that there would be 230 crossovers in one cell.
So these little chromosomes know what to do to make everyone a little more unique.
I'm tired, it's late at 12.20am and Im glad that I have finally finished my little study on Meiosis - at last. I found it a little frustrating but the motivation to write an article about it gave me a little encouragement. I hope that I have taught you well about this particular subject and I am sure that these facts are correct. I mean, I had a bloody Science Workbook with me guiding me throughout this article.
So thanks to the school for even supplying me with this workbook. It would help me a lot through the rest of my study.
And as I told you for the last article, I will tell you guys once again how to tell the differences between Meiosis and Mitosis.
How I remember it?
I just think Mitosis, my toes grow hence Mitosis is the cell division regarding growth! w00t! Smartass alert, heh?
I don't think it sounds very appealing but the mnemonic works!
Until next time.
Peace out and goodnight.