Question

A homozygous tall plant (T) bearing red coloured (R) flowers is crossed with a homozygous dwarf (t) plant bearing white (r) flowers :

(i) Give the genotype and phenotype of the plants of F₁ generation. 

(ii) Mention the possible combinations of the gametes that can be obtained from the F₁ hybrid plant. 

(iii) State the Mendel’s law of Independent Assortment. 

(iv) Mention the phenotypes of the offsprings obtained in F₂ generation. 

(v) What is the phenotypic ratio obtained in F₂ generation ?

Answer 1

(a) 

(i) Genotype of F₁ generation : Tt Rr Phenotype of F₁ generation : All heterozygous tall and red. 

(ii) TR: Tall and Red 

Tr: Tall and White 

tR: Dwarf and Red 

tr: Dwarf and White 

(iii) Mendel’s law of independent Assortment: “In a dihybrid cross, one pair of character is independent of the other pair during gamete formation.” 

(iv) Tall & Red 

Tall & White 

Dwarf & Red 

Dwarf & white 

(v) 9 : 3 : 3 : 1