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Guilherme Mazui

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What is the Difference Between Homozygous and Hemizygous?

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The difference between homozygous and hemizygous lies in the number of alleles present for a particular gene in an organism. Here are the key distinctions:

  • Homozygous: This refers to a genotype consisting of two identical alleles at a given locus. In homozygous genes, both alleles are either dominant or recessive, and the organism has two similar alleles for the same gene.
  • Hemizygous: This refers to a genotype consisting of only a single copy of a particular gene in an otherwise diploid organism. Hemizygosity can occur when one copy of a gene is deleted, or in the heterogametic sex, when a gene is located on a sex chromosome. There are two types of hemizygosity:
  1. Hemizygous dominant: The organism has only one copy of a dominant allele.
  2. Hemizygous recessive: The organism has only one copy of a recessive allele.

In summary, an organism is homozygous when it has two identical alleles for a particular gene, and hemizygous when it has only one copy of a gene, either with a dominant or recessive allele.

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  • What is the Difference Between Homozygous and Hemizygous?
  • Comparative Table: Homozygous vs Hemizygous

    • Comparative Table: Homozygous vs Hemizygous

    The difference between homozygous and hemizygous lies in the number of alleles for a particular gene in an organism. Here is a comparison table highlighting the differences:

    Feature Homozygous Hemizygous
    Definition Homozygous is the state of having similar alleles, either two dominant alleles or two recessive alleles. Hemizygous is the state of having only one copy or allele of a gene.
    Alleles Two copies of the same allele of a gene. One copy of a gene.
    Types Homozygous can be either homozygous dominant (e.g., AA) or homozygous recessive (e.g., aa). Hemizygosity can have either a dominant allele or a recessive allele.
    Notation Homozygous can be depicted as XAXA or XaXa. Hemizygous can be depicted as XaY or XAY.

    In summary, homozygous refers to having two identical alleles for a gene, while hemizygous refers to the presence of only one copy of a gene in an organism.

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    Guilherme Mazui

    Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.