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Why are family members different?

  1. Oct 8, 2018 #1
    i mean why is my brother physically different then me. why aren't we twins by default? don't we have the same chromosomes inhererented from our parents?

    aren't zygotes the same from the start?

    dumb question prolly, but i do not have the answer.

    are chromosomes copied with errors or something or are other factors come into play?

  2. jcsd
  3. Oct 8, 2018 #2
    Homologous chromosomes is separated while sperms and eggs are generated,and the two separated string will enter two different sperms or eggs,which essentially means that your om and dad are flipping coins on every one of your body features,which makes you and your brother different,cause there coin flipping results re different.
  4. Oct 8, 2018 #3


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    During meiosis, which is the type of cell division that creates gametes (sperm and eggs), genetic recombination occurs that takes DNA from one-half of a chromosome and copies it to the other. Each chromosome is composed of a pair of chromatids, which are the 'arms' and 'legs' of a chromosome. For each chromosome, you get one chromatid from your father and one from your mother. Recombination swaps DNA between each chromatid so that the new chromatids are unique and different from either of the parent chromatids.

    In other words, the DNA from your parents is mixed together and a unique combination comes out of the process, which is where the differences between siblings comes from.

    See this link for more info: https://en.wikipedia.org/wiki/Chromosomal_crossover
  5. Oct 9, 2018 #4
    Way more professional then me!!!
  6. Oct 9, 2018 #5
    thanx for the answers
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