{"id":4512,"date":"2017-03-23T18:36:34","date_gmt":"2017-03-23T18:36:34","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/wm-biology1\/?page_id=4512"},"modified":"2017-03-23T18:36:34","modified_gmt":"2017-03-23T18:36:34","slug":"practicing-non-mendelian-inheritance","status":"publish","type":"page","link":"https:\/\/courses.lumenlearning.com\/suny-wmopen-biology1\/practicing-non-mendelian-inheritance\/","title":{"rendered":"Practicing Non-Mendelian Inheritance"},"content":{"rendered":"

Gregor Mendel is known as the father of genetics. His experiments\u00a0with\u00a0pea plants\u00a0created the foundation for our modern understanding of genetics. However, as with most scientific ideas, Mendel didn’t quite have the whole picture. Over the years, geneticists have found that not all\u00a0traits have simple\u00a0dominant\/recessive traits. These\u00a0cases of non-Mendelian inheritance are often sorted into three categories: incomplete dominance, codominance, and sex-linked traits.<\/p>\n

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Practice Question<\/h3>\n
\"The<\/p>\n

Figure 1. In this cross, the red and white parents have all pink offspring.<\/p>\n<\/div>\n

Which type of inheritance do you think is shown in Figure 1?<\/p>\n

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  1. incomplete dominance<\/li>\n
  2. co-dominance<\/li>\n
  3. sex-linked trait<\/li>\n<\/ol>\n
    Show Answer<\/span><\/p>\n
    This is an example of incomplete dominance.<\/div>\n<\/div>\n<\/div>\n

    Incomplete Dominance<\/h2>\n

    In incomplete dominance,\u00a0two phenotypes (like\u00a0the red and white petals in Figure 1)\u00a0are equally dominant, so the colors blend together\u00a0in the offspring’s pink petals. Another example of incomplete dominance can be found in rabbits: when a long-furred Angora breeds with a short-furred Rex, the offspring have medium-length fur.<\/p>\n

    Co-dominance<\/h2>\n

    Now that we’ve talked about incomplete dominance, let’s look at co-dominance. If the parent flowers from Figure 1\u00a0had co-dominant inheritance, what do you think the offspring would look like the\u00a0flower in Figure 2.<\/p>\n

    \"A<\/p>\n

    Figure 2. This flower exhibits co-dominance<\/p>\n<\/div>\n

    Another example of co-dominance is blood typing in human beings. Ignoring positive and negative blood typing, there are four\u00a0blood types:<\/p>\n

      \n
    • Type A (IA<\/sup>IA<\/sup>, IA<\/sup>i)<\/li>\n
    • Type B (IB<\/sup>IB<\/sup>, IB<\/sup>i)<\/li>\n
    • Type AB (IA<\/sup>IB<\/sup>)<\/li>\n
    • Type O (ii)<\/li>\n<\/ul>\n
      \n

      Exercises<\/h3>\n

      Given these alleles, is it possible for a child with AB blood to have a parent with O blood?<\/p>\n