Anonymous asked in Science & MathematicsBiology · 1 month ago

A male baby is born with the sex chromosomes constitution XYY. Both parents have normal sex chromosomes. ?

What statements most likely explain this unusual observation?

7 Answers

  • Anonymous
    3 weeks ago

    This happens sometimes and is called nondisjunction in meiosis I. There is nothing wrong with having an extra Y chromosome it does not affect you in anyway shape or form. :-)

  • Anonymous
    4 weeks ago

    The most likely explanation is that the mother cheated on the father, with a black guy.  Black guys sperm are all Y's, and there's so many of them, that two of them made it to the egg at the exact same time, hence the XYY

  • 1 month ago

    Non- disjunction of the Y chromosome during meiotic formation of the sperm.

  • 1 month ago

    Nondisjunction, or failure of chromosomes to separate correctly during meiosis, is the cause of this constitution. However, the nondisjunction event had to take place in the formation of a sperm since eggs do not have Y chromosomes at all.

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  • Zirp
    Lv 7
    1 month ago

    Yes, parents of such boys usually have perfectly normal chromosomes, and so do those boys themselves. Those boys merely have a Y-chromosome too many because of a production-error in the father

    When I wrote:

    Anonymous, where would the Y-chromosome in a woman's reproductive cell come from?

    3 people thumbed it down. Maybe they believe that women have a Y-chromosome too?

  • 1 month ago


  • Anonymous
    1 month ago

    Boys who have XYY syndrome are born with it. It's called XYY because they have an extra Y chromosome in most or all of their cells.

    Usually, a person has 46 chromosomes in each cell, divided into 23 pairs, which includes two sex chromosomes. Half of the chromosomes are inherited from the father and the other half from the mother. The chromosomes contain genes, which determine an individual's characteristics, such as eye color and height. Boys typically have one X chromosome and one Y chromosome, or XY, but boys with XYY syndrome have an extra Y chromosome, or XYY.

    XYY syndrome is not caused by anything the parents did or did not do. The disorder is a random error in cell division. This error can happen before conception in the reproductive cells of the mother or the father, or early in the embryo's development.

    When the extra chromosome is the result of incorrect cell division early in the embryo's development, a boy may have a mosaic form of XYY syndrome. This means some of the cells have an extra Y chromosome, but not all do. Boys with mosaic XYY syndrome usually have fewer symptoms.

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