The basics. |
An introduction to DNADNA is probably the most important part of your body, but you can't see it. DNA is short for deoxyribonucleic acid. DNA is formed of nitrogenous base pairs that have been given the names, A,T,C, and G. combinations of these four letters contain the instructions to make every living thing on earth. This system works incredibly well and is able to store humongous amounts of information in tiny cells, but like everything it is not perfect, sometimes it makes mistakes and causes Mutations.
What is MeiosisMeiosis is the process that creates sex cells, sperm and eggs. Meiosis is unique because it creates 4 special cells with only 23 chromosomes each. These cells become either sperm or eggs. the process is special because it goes through mitosis two times, one cell splits to make 2 and 2 split to make 4. But its what happens in the first division that is special. When the chromosomes are lined up in prophase they share information between each other before moving across the cell. This is called crossing over and it is where most mutations occur. Because these cells will go on to make an entire human then any mutation here will go into every cell of the new person.
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Mitosis and it's stagesMitosis is the act of cells splitting, this is happening right now in your body and has been happening for your entire life. When a cell has reached the end of its life it prepares to split into two new cells, this is Mitosis. Mitosis has 5 stages, prophase, metaphase, anaphase, telophase, and cytokinesis. In prophase the nucleus of the cell dissolves and the DNA stored there forms into chromosomes. In metaphase the chromosomes line up and are grabbed by spindles. In anaphase the chromosomes are pulled to opposite sides of the cell and the cell begins to widen. In telophase new nucleuses form around the split chromosomes and the cell begins to split. Finally in cytokinesis the cell splits and two cells remain in the place of one.
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What are mutations
Mutations are mix ups in your genetic code. Because all of the code in your body must be copied over completely for each new cell you have there are bound to be mix ups. Most mutations only change a single letter from one to another but that is enough to change your life. Mutations happen all the time, in fact, you have at least 60 mutations that you did not inherit from either of your parents. Most of these mutations will be harmless, this is because your cells are specialized and only use some of your DNA in their job. For example, a mutation that affects your hair would not do anything if it occurred in a stomach cell.