What is the difference between the Principle of Dominance and the Principle of Segregation?

Answer 1

These are principles which Gregor Mendel discovered when he carried out his experiments on inheritance in pea plants.

Mendel discovered that each character eg height of the plant, is controlled by two genes (which he called 'factors'), one from each parent. The Law of Segregation states that when gametes (sex cells: eggs and sperm) are produced, the two genes in each pair separate (segregate) and go to different cells. This means that eggs and sperm end up with only one copy of each gene, instead of a pair of genes.

Mendel also discovered that genes occurred in alternative versions which we call alleles eg the height gene can be the tall allele or the short allele. If an individual plant inherits one tall allele and one short allele, the tall allele 'hides' the short allele and the plant is tall. The tall allele is called the dominant allele. Dominant alleles only need to be inherited from one parent to produce an effect.

The short allele is called the recessive allele. A recessive allele must be inherited from both parents in order to produce an effect.