Q:

Why is crossing over important in meiosis?

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Quick Answer

Crossing over in meiosis results in genetic recombination, which is responsible for the genetic diversity of a population. Genetic recombination and natural selection are the driving forces behind evolution. It causes most of the differences between parents and their offspring and differences between siblings.

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Why is crossing over important in meiosis?
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Full Answer

Meiosis, otherwise known as sex cell division, creates unique gametes, which are eggs in females or sperm in males, from existing DNA in eukaryotes. For meiosis to occur, the chromosomes contributed by each of the organism's parents are duplicated to form sister chromatids. During meiosis I, the sister chromatids of one parent match up with the corresponding sister chromatids of the other parent, or its homologous non-sister chromosome, along the metaphase plate. Crossing over then occurs. At a point called a chiasma, homologous chromosomes trade genetic information so that each chromosome is complete but has different information. This random exchange of information is what allows for unique gametes to form and genetic recombination to occur.

Sometimes, however, too few crossing over events can result in abnormally short or long chromosomes, meaning that there is too little or too much information. If a gamete with this type of chromosome is fertilized, abnormalities in the offspring are likely.

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Related Questions

  • Q:

    Why is meiosis important?

    A:

    Meiosis is important because during sexual reproduction, it ensures that all produced organisms have the correct number of chromosomes. It is also responsible for producing genetic variations during the process of recombination, and it repairs some genetic defects.

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  • Q:

    Where does meiosis occur?

    A:

    Meiosis occurs in the reproductive organs of all males and females. The process of meiosis results in the formation of gametes. Gametes are the reproductive cells called sperm in males and ova or eggs in females.

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  • Q:

    What is the purpose of meiosis?

    A:

    Meiosis is the process of cell division that creates offspring in sexually reproducing organisms, explains a University of Illinois at Chicago website. Unlike during mitosis, meiotic cell division starts with double the number of chromosomes in diploid parent cells. Meiosis cuts this number in half forming two haploid daughter cells. When these daughter cells combine and undergo fertilization, a zygote is created and the cell begins to develop.

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  • Q:

    How do I describe meiosis?

    A:

    Meiosis is the process in which cells divide to produce sex cells. Meiosis takes a single cell and divides it into four different cells with half of the necessary chromosomes for human development. Meiosis creates both egg and sperm cells.

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