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

Mendelian pattern of genetics remains the most followed trend for explaining various aspects of genetic inheritance. However, some exceptions to the patterns do exist. These patterns help us understand the manner in which some diseases are expressed in individuals. Some of these exceptions can be discussed as below:

1. Co-dominance: Co-dominance is a type of pattern of inheritance in which the two alleles for a phenotype express themselves equally, thus giving rise to a different type of phenotye than normal. For example, the human blood group system comprises of three alleles, A, B and O where A and B are co-dominant over each other and both of them are completely dominant over O. Thus, the human blood groups contain 4 types, A, B, AB and O. This pattern is different from normal Mendelian pattern where only three phenotypes would have existed.
2. Incomplete dominance: In this exception, the two alleles for the phenotype are not completely dominant over each other and when they come together as a genotype, they give rise to a third type of phenotype as compared to normal dominant and recessive. This pattern is usually seen in pea plants where red adn white flowers are dominant and recessive, respectively, but the combination of the alleles from each of them gives pink flowers, not red flowers. Hence, this accounts for an exception from normal Mendelian pattern of inheritance.

These are some of the examples which demonstrate the exceptions from Mendelian patterns of inheritance.