The given information states that the purebred long and sticky seed (P) is completely dominant over the short and dry seed (p). The F1 generation obtained from the cross between P and p shows 50% long and sticky seeds and 50% short and dry seeds.

Based on this information, we can determine the genotypes of the parents (P and p) as follows:

P: Purebred long and sticky seed (homozygous dominant) - PP
p: Purebred short and dry seed (homozygous recessive) - pp

The F1 generation will have the genotype Pp, as it received one dominant allele (P) from the purebred long and sticky seed parent (P) and one recessive allele (p) from the purebred short and dry seed parent (p).

To determine the genotypes and phenotypes of the F2 generation, we can use a Punnett square:

Pp x Pp

P p
P PP Pp
p Pp pp

From the Punnett square, we can see that the F2 generation will have the following genotypic and phenotypic ratios:

Genotypic ratio:
1 PP : 2 Pp : 1 pp

Phenotypic ratio:
3 long and sticky seeds : 1 short and dry seed

Therefore, the F2 generation will consist of 75% long and sticky seeds and 25% short and dry seeds.