A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the plants ?

Options

A. TT and Tt
B. Tt and Tt
C. TT and TT
D. Tt and tt

Answer

B

Explanation

Tt and Tt let's use Mendel's cross of tall and and dwarf pea plants as an example. The `F_(1)` plants of genotype Tt are self-pollinated. (both tall (T) but with dwaft (t) alleles).

The letters T and t are used to represent the gene that determine plant height by conventions. The upper case letter (T) repersents the dominate allele and the recessive allele (t) is represented by the same letter in lower case.
Thus, the tall parents plants having heferozygous alleles, results in offsprings whihc comprises of both tall and dwarf plants.
For the parental cross, both the parents are true breeding plants, the tall plant is homozygous for the tall allele 'T', while the dwarf plant is homozygous for the dwarf allele 't'. Mendel tracked each trait through two generations.
When true breeding plants were crossed to each other, this is called a parental cross and offspring comprise the first filial or `F_(1)`-genration. When the members of the `F_(1)`-generation were coossed, this peoduced the `F_(2)`-generation or second filial generation.
A cross between true breeding tall and dwaft plants of the parent generatin yield phenotypically tall plants.
The cross between TT and Tt is called back cross, which results into two homozygous and two heterozygous dominant gametes. The cross between Tt and it is called test cross which results into 1:1 ratio of gametes.