A tall looking pea plant can have a genotype of Tt or TT.
The genotype of the tall pea plant is heterozygous
The genotype of the tall pea plant is heterozygous!
When a true breeding tall pea plant (homozygous for the tall trait, TT) is crossed with a tall pea plant of unknown genotype, the offspring's phenotypes can help determine the genotype of the second plant. If all offspring are tall, the unknown plant is likely also homozygous tall (TT). However, if some offspring are short, the unknown plant must be heterozygous (Tt), as the short trait (tt) can only appear if the recessive allele is present. In summary, the resulting phenotypes of the offspring will clarify the genotype of the unknown parent.
homozygous- TT; heterozygous- Tt :)
TT or Tt
Tt
For example, if the tall plant stand for T, the genotypes are: TT tt
false
Three types of genotypes that exist for pea plant height are: TT - Homozygous dominant genotype for tall height Tt - Heterozygous genotype for tall height tt - Homozygous recessive genotype for short height
In the case of simple dominance, the tallness trait (T) is dominant over the shortness trait (t). Therefore, a pea plant with the genotype Tt will exhibit the tall phenotype, as the presence of one dominant allele (T) is sufficient to express the tall trait. Thus, the plant with genotype Tt will be tall.
In pea plants, the trait for tallness is typically dominant, while the trait for shortness is recessive. In a case of simple dominance, a plant with a genotype that includes at least one dominant allele for tallness (e.g., TT or Tt) will be tall. Conversely, only a plant with the homozygous recessive genotype (tt) will be short. Thus, a plant with the genotype TT or Tt will be tall.
Really, there is no set letter for any allele. It is common, however, to use the first letter of the dominant allele. Since tall height is dominant over short height in pea plants, then the allele for short would be the t (a lowercase t).