Make a Punnett square for finding out the proportion of different genotypes in the progeny of a genetic cross between

(a) A pure tall (TT) pea plant with a pure dwarf (tt) pea plant.


(b) Red flower variety of pea (RR) with white flower variety of pea (rr).


(a)


In F2 generation


TT = Homozygous black = 1


Tt = Heterozygous black = 2


tt = Homozygous brown = 1


Thus, in F2 generation;


Genotype = 1 : 2 : 1


Phenotype = 3 : 1


(b)



In F2 generation


TT = Homozygous red flower = 1


Tt = Heterozygous red flower = 2


tt = Homozygous white flower = 1


Thus, in F2 generation;


Genotype = 1 : 2 : 1


Phenotype = 3 : 1


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