Mendel described how certain traits are passed on from one generation to the next.  He was the first to suggest that information is passed to the child in pairs, one from the father and one from the mother.  His most outstanding achievement was to recognise that genes can be dominant or recessive and that a dominant gene will suppress or disguise the recessive gene.

Within some of the papers that he presented he describes how genes for tall pea plants are dominant and those for short pea plants are recessive.  He also made a similar experiment to study the genes that define the colour of the pea (yellow or green).  Between 1856 and 1863, he cultivated over 25,000 plants to test his theories.

Mendel's 1st Law: The law of segregation.  This law states that during the creation of a Zygote from two gametes, the offspring acquires one copy of an hereditary factor from each parent. 

Mendel's 2nd Law: The law of independent assortment.  This law states that each individual hereditary factor will organise themselves independent of each other during the production of the zygote.  This means that all traits have an equal chance of occurring together so that you will never see an exact replica of one or other of the parents.

1. What is a blood type? 

2. How blood types are inherited

3. The Rh blood type system - positive or negative

4. Paternity testing and blood types

5. Examples of blood type inheritance

6. A quick history lesson