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Home > Science > What is the Difference Between Homologous Chromosomes and Sister Chromatids?

Guilherme Mazui

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What is the Difference Between Homologous Chromosomes and Sister Chromatids?

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The main difference between homologous chromosomes and sister chromatids lies in their genetic content and structure:

  • Homologous Chromosomes:
  • Composed of two different chromosomes that are not genetically identical, despite containing the same sets of genes.
  • Provide the basis for genetic diversity.
  • Separated during meiosis and distributed to different daughter cells.
  • One homologous chromosome is inherited from each parent in diploid organisms.
  • Homologous chromosomes have the same structure and gene content but can have different alleles.
  • Sister Chromatids:
  • Genetically identical copies of a single chromosome produced during DNA replication.
  • Ensure the accurate distribution of genetic information to daughter cells.
  • Separated during mitosis and distributed to each daughter cell.
  • Sister chromatids are exact copies of one another before crossing over.
  • Crossing over occurs between homologous chromosomes, not sister chromatids.

In summary, homologous chromosomes are pairs of chromosomes with the same structure and gene content but different alleles, while sister chromatids are genetically identical copies of a single chromosome. Homologous chromosomes ensure genetic diversity, while sister chromatids ensure the accurate distribution of genetic information to daughter cells.

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  • What is the Difference Between Homologous Chromosomes and Sister Chromatids?
  • Comparative Table: Homologous Chromosomes vs Sister Chromatids

    • Comparative Table: Homologous Chromosomes vs Sister Chromatids

    Here is a table highlighting the differences between homologous chromosomes and sister chromatids:

    Feature Homologous Chromosomes Sister Chromatids
    Definition A pair of one maternal and one paternal chromosome, paired during fertilization in a diploid cell. The two copies of one chromosome, linked together in the centromere.
    Connection Not connected with each other. Linked to each other by proteins called cohesins, via the centromere.
    Origin One homologous chromosome comes from the father's gametes, and the other comes from the mother's gametes. Each sister chromatid comes from either the father's or mother's gametes.
    Structure Identical in size, shape, and gene content. Formed during the S phase of the cell cycle when DNA replication takes place, composed of DNA and associated proteins.
    Separation Separated during meiosis and distributed to different daughter cells. Separated during anaphase of mitosis and meiosis II.

    Homologous chromosomes provide the basis for genetic diversity, while sister chromatids ensure the accurate distribution of genetic information during cell division.

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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.