How many different phenotypes and genotypes are obtained in the F2 generation of Mendel’s dihybrid cross?
How many different phenotypes and genotypes are obtained in the F2 generation of Mendel’s dihybrid cross?
The correct option is A 4 phenotypes and 9 genotypes
Mendel considered two traits- seed colour and type for his dihybrid cross. He crossed two pure-bred varieties round yellow seeded plants (RRYY) with the (rryy) wrinkled green seeded plants, and self-fertilized the F1 hybrids (RrYy). The Punnett square here shows the different combinations of F2 progeny obtained.
The F2 progeny of Mendel’s dihybrid cross exhibit four different phenotypes: round yellow, round green, wrinkled yellow and wrinkled green.
And 9 different genotypes:
- RRYY, RRYy, RrYY, RrYy - 4 genotypes of the round yellow phenotype
- RRyy, Rryy- 2 genotypes of the round green phenotype
- rrYY, rrYy- 2 genotypes of the wrinkled yellow phenotype
- rryy- 1 genotype of the wrinkled green phenotype
Thus 4+2+2+1 = 9 genotypes
Of the four phenotypes, two are parental types and two are recombinants. Out of the 16 genotypes, there are 9 different types.
4 phenotypes and 9 genotypes
Mendel considered two traits- seed colour and type for his dihybrid cross. He crossed two pure-bred varieties round yellow seeded plants (RRYY) with the (rryy) wrinkled green seeded plants, and self-fertilized the F1 hybrids (RrYy). The Punnett square here shows the different combinations of F2 progeny obtained.
The F2 progeny of Mendel’s dihybrid cross exhibit four different phenotypes: round yellow, round green, wrinkled yellow and wrinkled green.
And 9 different genotypes:
- RRYY, RRYy, RrYY, RrYy - 4 genotypes of the round yellow phenotype
- RRyy, Rryy- 2 genotypes of the round green phenotype
- rrYY, rrYy- 2 genotypes of the wrinkled yellow phenotype
- rryy- 1 genotype of the wrinkled green phenotype
Thus 4+2+2+1 = 9 genotypes
Of the four phenotypes, two are parental types and two are recombinants. Out of the 16 genotypes, there are 9 different types.
