He La cells have play important role in the study of cancer and even in cancer therapies. He La cells are also used to diagnose trisomic disorders such as Down's Syndrome with the help of chromosome banding. Some genes present in the He La cells are used as markers and compared with the other cell line in question. Presence of the marker for Down's syndrome in the cell in question shows that the person is suffering from the disease.
As you can see from the image presented below when parents with AB Ss and AA ss genotypes cross we get three distinct phenotype groups.
Marked in red are the individuals whose A type blood we can determine from the saliva because they have at least one S allele.
Marked in light green are the individuals whose AB type of blood we can determine from the saliva too.
And marked in orange are the individuals that are homozygous recessive for the s allele, and we could not determine their blood type from their saliva.
Xylem carries water and dissolved nutrients
I think it's A not sure tho