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    Hey, I have my biology unit 2 exam tommorow for gcse.

    I think i'm okay with everything and i just need to know how mitosis happens as i think i've confused myself a little bit.

    Does it go like this:

    First the Organelles copy, then the copies seperate and move towards opposite sides of the cell and then the cell divides into two?

    I'm not sure if the organelles are the chromosomes as in 1/2 of the "k" ( the shape the chromosome looks like when its been copied)
    Or are they different things, so after the organelles are copied, then the chromosomes are copied?!

    I was looking at my past paper and I just got this wrong, i totally don't understand, the order it should go in is " B,E,D,A,C."


    The statements describe how organisms produce new cells.
    They are in the wrong order.
    A The copies of chromosomes separate.
    B The number of organelles in the cell increases.
    C The cell divides into two cells.
    D Each strand is copied to make two new strands (chromosomes).
    E The two strands of each DNA molecule separate.
    Put the statements into the correct order. The first one has been done for you.


    Can somebody please explain why? I would be really grateful for your time and effort, as I do with most of my threads, i do actually +rep people who help me.

    Thanks
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    you've got it right with the letters. when dividing cells take part in the "cell cycle" the first 3 phases, G1, S and G2 are all part of interphase. in G1 the organelles copy, in S the chromosomes duplicate, and in G2 the cell undergoes checks for faults. then mitosis occurs, which is split into 4 parts, prophase: where the nuclear envelope disappears revealing the 2 sets of chromosomes. metaphase, where the chromosomes line up on the equator of the cell, anaphase where they chromasomes are pulled apart to opposite sides of the cell and finally telophase the nucleus reforms around the 2 sets of separate chromosomes. after this cytokinesis occurs (splitting of the cytoplasm) and thats cell division in a nutshell
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    (Original post by Artymess)
    you've got it right with the letters. when dividing cells take part in the "cell cycle" the first 3 phases, G1, S and G2 are all part of interphase. in G1 the organelles copy, in S the chromosomes duplicate, and in G2 the cell undergoes checks for faults. then mitosis occurs, which is split into 4 parts, prophase: where the nuclear envelope disappears revealing the 2 sets of chromosomes. metaphase, where the chromosomes line up on the equator of the cell, anaphase where they chromasomes are pulled apart to opposite sides of the cell and finally telophase the nucleus reforms around the 2 sets of separate chromosomes. after this cytokinesis occurs (splitting of the cytoplasm) and thats cell division in a nutshell
    woah okay i kinda get that, but i don't think i need to be this specfic though! could you simplify this down a bit, i get what your saying, as the organelles copy and then are you saying that the chromosomes are also copied?
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    youtube vids are good, just search "mitosis"
    example: http://www.youtube.com/watch?v=VGV3fv-uZYI
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    (Original post by d_aan)
    woah okay i kinda get that, but i don't think i need to be this specfic though! could you simplify this down a bit, i get what your saying, as the organelles copy and then are you saying that the chromosomes are also copied?
    sorry, i get a tad carried away with biology. basically the organelles are copied first, then the chromosomes are copied. after this the nucleus disappears leaving just 2 sets of chromosomes, which move to opposite sides of the cell and form nuclei of their own (so now the cell has 2 nuclei). its after this the cell divides so each daughter cell has both a nucleus with 46 chromosomes and a sufficient number of organelles
 
 
 
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