Biology question?!?!?!

okay i usually don't ask for help on homework and stuff but this is very confusing. So this is the question :

Explain how the following traits do not follow the rules of simple Mendelian genetics (i.e. dominant&recessive). Give an example of what might occur in the offspring generation of 2 parents with the following types of traits.
1.incomplete dominance
2.codominance
3.multiple alleles
4.polygentic traits

.....okay so thats what the question is..what am i supposed to do? and if you could, could you give me the answer to 1,2,3, or 4 as an examples? thankyou (:

Here are some examples to set you on the right path:
Mendelian genetics say that when you have a dominant allele, something is expressed and when you have homo recessive, something else is expressed. However only one is expressed at a time.
For 1. This does not follow Mendelian genetics because lets say the dominant allele codes for black fur and the recessive codes for white fur. Incomplete dominance is when it codes for gray fur. It is a mixture. Both are expressed, and mixed.
For 2. Co-dominance is where they both are expressed by themselves. For example, black and white patches as opposed to mixture on gray. Both alleles are present however not just one is expressed.

1 some pigments in the flower are expressed by one gene, let A be the "dominant" allele and a the recesive, so if the flower has AA it´s red, if has aa is white, but if has Aa it´s pink, (so the dominance os A is not as complete as the mendel case)

2, 3 in the blood there are several aleles (not only 2 as every case in mendel), A B and O, that determines the blood type, if an human gets AO or AA he´ll be Rh A, if he´s BO or BB, he´s B, If he´s OO he gets O, but if he is AB, he will get AB blood type (that´s the codominance)

for 4 i have no examples, sorry