Gregor Mendel has discovered that biological inheritance is determined by genes, which are passed from one generation to the offspring.

Gregor Mendel has discovered that biological inheritance is determined by genes, which are passed from one generation to the offspring. Every gene is determined by alleles, which represent different variants of a certain trait. These alleles can be dominant and recessive. The offspring will inherit two alleles, one from each parent, that determine its appearance. In the parental generation occurs formation of gametes which contains only one, randomly chosen allele. That process is called segregation.

Self-pollination is a process of plant breeding where there is only one parent, which means that an offspring will have the same appearance as the parental generation. Cross-pollination is a process of plant breeding with two different plants, which creates an offspring with different traits than the parental plant. Plants that are produced in this way are known as hybrids. Cross-pollination contributes to the genetic diversity.

Pea flowers reproduce by self-pollination, while Mendel explored cross-pollination in pea flowers with various traits. He pollinated one flower by the other with different characteristics. Plants that are produced in this way are known as hybrids. For example, two yellow peas give a yellow offspring in 75% and the green one in 25%. The offspring inherits two alleles, one from each parent, that determine its appearance. In the parental generation occurs formation of gametes which contains only one, randomly chosen allele. That process is called segregation. The dominant allele determines the yellow, while the recessive allele determines green color. When a plant inherits one, or two dominant alleles from its parents, that will define the yellow color. The appearance of the offspring will be green only if the recessive allele is inherited from both of the parental plants.

The offspring inherits two alleles, one from each parent, that determine its appearance. The dominant allele determines the tallness, while the recessive allele determines shortness. When a plant inherits one, or two dominant alleles from its parents, that will define the tallness. The shortness of the offspring will appear only if the recessive allele is inherited from both of the parental plants. We have several possibilities:

parental: TT – TT offspring: TT TT TT TT
parental: Tt – Tt offspring: TT Tt Tt tt
parental: TT – Tt offspring: TT Tt TT Tt

The offspring inherits two alleles, one from each parent, that determine its appearance. The dominant allele determines the tallness, while the recessive allele determines shortness. When a plant inherits one, or two dominant alleles from its parents, that will define the tallness. The shortness of the offspring will appear only if the recessive allele is inherited from both of the parental plants. We have several possibilities:

parental: TT – TT offspring: TT TT TT TT
parental: Tt – Tt offspring: TT Tt Tt tt
parental: TT – Tt offspring: TT Tt TT Tt