Question

In Mendel's monohybrid cross of purple-flowered and white-flowered peas, all members of the F1 generation had the __________ phenotype because their genotype was __________ at the flower-color locus.

Answer 1

In Mendel's experiment, the F1 generation had all purple flowers due to the dominant purple trait, and their genotype was heterozygous. The white flower trait reappeared in the F2 generation, showing it was recessive and not lost.

Step-by-step explanation:

In Mendel's monohybrid cross of purple-flowered and white-flowered peas, all members of the F1 generation had the purple phenotype because their genotype was heterozygous at the flower-color locus. This was because the purple flower color trait is dominant over the white flower color trait. Mendel confirmed that, other than flower color, the pea plants were physically identical. After pollinating a white-flowered plant with pollen from a purple-flowered plant, all resulting F1 generation offspring had violet flowers, with none exhibiting the expected blending of traits. Moreover, when the F1 plants self-fertilized, the F2 generation exhibited a 3:1 ratio, where approximately 75% had purple flowers and 25% had white flowers, demonstrating that the white flower trait had not disappeared but was recessive.

Answer 2

All members of the F1 generation had the Purple phenotype because their genotype was Pp at the flower locus.

Step-by-step explanation:

Monohybrid cross is a cross involving one trait(for example Flower color).

When Mendel crossed true breeding pea plants that differed in flower color ie Purple flowered pea plant(PP) is crossed with White flowered pea plant(pp),all the seeds of F1 generation were purple.

The white flower trait did not appear in the F1 generation because the purple flower trait completely masked the white flower trait . Thus ,Purple flower trait (PP) is dominant over white flower trait(pp).

So,although the genotype of F1 seeds is Pp,the phenotype is purple flower color because the allele" P" is completely dominant over the allele "p".