Answer:
Mendel is known as the father of genetics. He explained the law of segregation by the monohybrid cross. The monohybrid cross involves the cross of a single trait at a time.
Law of segregation explains that at the time of formation of gametes, the allele pairs get separated from the pairs of trait. The concept of dominance was also explained. The traits that express itself even in the heterozygous condition is known as dominant trait (T). The trait that can not express itself is known as recessive trait (t).
For example:
Parents TT × tt. (Laws of segregation)
Gamete T t
F1 generation Tt.
Selfing of F1 generation
Tt × Tt
Offspring : TT (tall) , Tt (tall) , Tt (tall) , tt (dwarf).
The phenotypic ratio is tall : dwarf (3 : 1)