1. This is a monohybrid cross.
2. F2 generation means cross between two heterozygous plants from F1 generation, so, cross between two yellow seeded plants with heterozygous genotype (Yy) will give 3 yellow seeded plants and 1 green seeded plant.
The phenotypic ratio is 3:1
the genotypic ratio is:- 1:2:1 (1 YY, 2 Yy, 1 yy)