Having a dimpled cheek is a dominant trait (d) and having a non-dimpled cheek is a recessive trait (d). if someone is homozygous dominant, then what genotype does the person carry?

The genes of an organism can be either a homozygous or a heterozygous one. When someone is a homozygous dominant, it means that it has two copies of the same dominant allele. Homozygous means that the organism has exact copies of the same gene allele. 

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.