Final answer:
The notation TT to geneticists indicates two dominant alleles, meaning the organism is homozygous dominant.
Step-by-step explanation:
The notation TT means to geneticists that an organism has two identical alleles that are dominant for a specific gene, making the organism homozygous dominant for that gene. This can be contrasted with tt, which would indicate a homozygous recessive condition, and Tt, indicating heterozygosity, where the organism has one dominant and one recessive allele.
When an individual has two dominant alleles, it is hemozygous dominant; an individual with two recessive alleles is called homozygous recessive. An individual carrying one dominant and one recessive allele is referred to as heterozygous. An example of a heterozygous genotype is Aa, not aA, as a dominant trait when written in a genotype is always written before the recessive gene in a heterozygous pair.