A monohybrid cross is a mating between two individuals with different alleles at one genetic locus of interest.
The expected genotype ratio when two heterozygotes are crossed is 1 (homozygous dominant) : 2 (heterozygous) : 1 (homozygous recessive).
Parents- Tt x Tt
Gametes- T, t T, t
Offspring- TT, Tt, Tt and tt
Phenotype- Tall, Tall, Tall and Dwarf
Genotypic Ratio- 1 : 2 : 1
Phenotypic ratio- 3 : 1