Inheritance controlled by dominant and recessive paired alleles is often referred to as simple Mendelian genetics. Many inherited patterns are more complex that those studied by Mendel.

Read About Complex Patterns of Heredity on pages 177, 178 & 179 of your textbook Use this information to create a “Main Idea” chart like the one shown above in your notebook

In Mendel’s pea-plant crosses, one allele was completely dominant over another.

In some organisms, however, an individual displays a trait that is intermediate between the two parents, a condition known as Incomplete Dominance

However, when you cross 2 of the F 1 ’s, you end up with a 1:2:1 phenotypic ratio;

In the monster world, fang length is an example of incomplete dominance. For example, if a homozygous long fanged monster (L L) is crossed with a homozygous recessive short fanged monster (L I L I ), all of the F 1 offspring have medium length fangs. In your notebook create a Punnett square illustrating this cross

Now, in your notebook create a Punnett square that shows the cross of 2 of the F 1 offspring

How many long Fanged monsters will appear in the F2 generation? Short fanged monsters? How many F2 monsters will have medium length fangs?

For some traits, two dominant alleles are expressed at the same time. In this case, both forms of the trait are displayed, a phenomenon called Codominance.

In monsters, purple people-eaters and green people-eaters are homozygous for the P and G alleles. If you cross a purple people-eater with a green people-eater, you get a people-eater with spots. In your notebook create a Punnett square to show the cross of a purple people eater with a green people-eater.

Now, in your notebook create a Punnett square that shows the cross of 2 of the F 1 offspring from the previous problem

The situation of human ABO blood groups is an example of codominance. Different combinations of the three alleles I A, I B, and i result in four different blood phenotypes, A, AB, B, and O. For example, a person with the alleles I A and i would have blood type A.

A man with AB blood marries a woman who has type O blood. What are the possible blood types of their children?

A man who has type A blood, marries a woman who has type B blood. Their first child has type O blood. How is this possible? If they were to have more children, what possible blood types might these children have?