Question

we learned not only about the importance of Mendel's Laws (segregation and independent assortment) to heredity, but also that there are a number of exceptions to Mendel's Laws. Inheritance follows some basic ideas, but can certainly appear to be a tricky thing if you don't fully understand the basis of how the traits of living things come about. This discussion, therefore, will focus on the exceptions to Mendel's Laws so that it will help you better understand how traits come about. You should look up more information on an exception and provide us with a better understanding of it in your postings. Different examples, importance, effects on traits including diseases, and other things can certainly be addressed. Please let me know if you have any questions on this interesting and relevant topic. I need 2 outside sources with IN-Paragraph citation as well as an ending citation. Use your words.. We also use https://openstax.org/details/concepts-biology

Answer 1

Although most of the forms of genetic inheritances follow Mendelian pattern of inheritance, some exceptions do exist in nature. Some of these exceptions can be discussed as below:

1. Incomplete dominance: Unlike complete dominance or normal cases of inheritance, the dominant trait is completely dominant over the recessive one, hence the heterozygous conditions (say Aa) gives rise to a dominant phenotype giving the phenotype ratio be 3:1. However in incomplete dominance, the dominant allele is not completely dominant over the recessive and the heterozygous condition gives rise to another phenotype, intermediate of the dominant and recessive, thus altering the ratio to be 1:2:1.

2. Co-dominance: Unlike normal dominance-recessive patterns, the concept of co-dominance gives rise to a mixed phenotype when two alleles for a trait are present in the cell. For example, human blood groups are encoded by alleles A, B or O, where A and B are co-dominant thus producing phenotype AB when present together and completely dominant over O thus the heterozygous condition of AO or BO always gives phenotype A and B, respectively. Thus, this pattern also shows a strong deviation from Mendelian inheritance.

Thus, these are some of the example which show deviation from normal inheritance patterns.