Genetics Phenotype Genotype question>?

The possible genotypes for deep-lobed leaves are DD and Dd.
The possible genotype for shallow-lobed leaves is dd.

The cross is the following:  Dd x Dd
This will yield a 3:1 phenotypic ratio (3 deep and 1 shallow)
The genotypic ratio is 1:2:1 (1 DD, 2 Dd, 1 dd)

Genotype deals with the actual alleles in the plant which are represented by capital and lowercase letters. The plant can be DD (homozygous dominant: Deep lobed) Dd (heterozygous: Deep lobed) or dd (homozygous recessive: Shallow Lobed)

The phenotype is the actual trait (deep lobed or shallow lobed) A simple 4 square Punnet will tell you the if two heterozygous plants were crossed (Dd x Dd) The possible outcomes are DD, Dd, Dd, an dd. So there is a 3:1 ratio of deep lobed: shallow lobed offspring.

deep lobed leaf (D)
shallow-lobed leaf (d)

D always trumps d in expression.
Genotype is the actual genetic pairs.
Phenotype is what you see.
Heterozygous means Dd or dD

Genotypes of deep-lobes:  dD or Dd
Genotypes of shallow-lobed can only be dd because if a dominant D was in the genetics, it would be expressed as a deep-lobed.

So if you are cross pollinating deep-lobed leaves and shallow lobed leaves:

Dd x dd = Dd + Dd + dd + dd - so half would be deep, half shallow or 50:50 ratio.

If you cross two heterozygous plants (which can only be deep-lobed)

Dd x Dd = DD + Dd + dD + dd - 3:1 ratio (the first three are deep the last shallow)

genotypes are the genetic combinations. because D is dominant, possible genotypes for a plant with deep lobed leaves are DD and Dd, whereas the only possible genotype for a plant with shallow lobed leaves is dd.

the answer to the next one is hard to know to because it doesn't specify what genotype it is cross-pollinated with.  if it was with a DD plant, every F1 offspring would have deep lobed leaves. if it was with a Dd plant, there would be a ratio of 3 deep lobed to 1 shallow lobed. finally, if it was crossed with a dd plant, it would produce 2 deep lobed to 2 shallow lobed. if you are having trouble seeing why, try making punnett squares.