Monday, November 23, 2015

Mitosis: The Movie Blog Entry


  • If a cell contains a set of duplicated chromosomes, does it contain any more genetic information than the cell before the chromosomes were duplicated?

I believe that the cell does not contain any more genetic information after DNA has been duplicated than the cell prior to the duplication because there is no more content to the DNA, only two exact copies of the same coding for genes. This can be compared to a class reading a paper. Though there will be many copies of the paper, the words on the page and information stored within that page is the exact same for everyone and does not increase or decrease in value depending on how many copies of it there are.


  • What is the significance of the fact that chromosomes condense before they are moved?
The fact that chromosomes condense before they move is significant because it is the condensing of the chromosomes that makes the splitting of the sister chromatids so much easier. If the strands were lined up in the middle of the cell during metaphase as the long strings that they normally exist in, and then tried to condense, there would be nothing for the spindle fibers to grab onto and it would also impede the fibers' process.

  • How are the chromosome copies, called sister chromatids, separated from each other?
Because the chromatids are linked by the centromere and brought to the middle of the cell by the spindle fibers, they are held tightly in place in the metaphase plate. When it is time to split, the enzyme separatase is activated, cutting the centromere bonds of the two chromatids and immediately enzymes within range of the spindle fibers on the chromosomes began to eat the fibers, thus drawing each separate chromatids closer to its respective ends.

  • What would happen if the sister chromatids fail to separate?
IF the sister chromatids failed to separate, then one cell would have a chromosome more than normal, and the other would have one less than normal. Because they store the genetic material for life on these chromosomes, cells cannot function well without even a single chromosome. They will produce incorrect proteins and could present horrible defects for the entire organism, especially if the sex cell that created the organism had one more or one less chromosome. An example of this would be down syndrome in humans. For people with down syndrome, when their parents sex cells came together, one had an extra copy of chromosome 21. If one of the first 15 or so chromosomes in the human genome have an extra copy or are missing one of the air, the cell will die because their cells just cannot function with that inherent problem.

  • What events could promote genetic variation during mitosis?
There are not many events that could promote genetic variation directly during mitosis because the cell has already replicated the DNA and encoded mutants, which is the primary cause for genetic variation. But during mitosis, the splitting and replication of mutant cells promotes genetic variation because then the mutation spreads through the body or to other tissues and if it it compatible and advantageous, could be kept in the organism.

  • What problems could occur with a loss of cell cycle control?
The biggest problem that occurs with a loss of cell cycle control is cancer. With cancer, the cells never stop dividing and spreading, causing major harm to the host and using up a lot of the bodies resources. But even if the process went the other way and one's body couldn't get its cells to replicated to replace tissues lost due to damage or the cells coming to the end of their life span, then the body would die because eventually all the cells in the body would perish and there would be nothing to replace them with.


Link to my group's mitosis movie:

https://www.youtube.com/watch?v=iRTmGbMQ4A0&feature=youtu.be

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