Mendel crossed yellow-seeded and green-seeded pea plants and then allowed the offspring to self-pollinate to produce an f2 generation. the results were as follows: 6022 yellow and 2001 green (8023 total). the allele for green seeds has what relationship to the allele for yellow seeds?

So Mendel got roughly 75% yellow and 25% green in f2.  This means that f1 contains all heterozygous genes, as shown below

       Y      y
Y    YY   Yy
y     Yy    yy
Summary: 75% YY or Yy, 25% yy

Which means that green (y) is a recessive phenotype, while yellow  (Y) is a dominant phenotype, since plants with heterozygous genotype Yy express the yellow trait.

They include lobsters and crabs