In the pair Tt the capital T represents what gene?

Answer 1

I'm not 100% sure what you're talking about here, but this looks like alleles, not genes. For every gene, there is one copy on each of a pair of chromosomes. The gene can take different forms, called alleles. In the "simple" case, there are only two possible alleles - dominant and recessive. When geneticists are analyzing the probability that an offspring will have the trait in question, they use a capital letter to indicate the dominant allele and a lower-case letter to indicate the recessive allele. The letter used is usually somehow representative of the trait. For Example, T (whether upper or lower case) might refer to a gene that has something to do with tongue. But there is no standard set of letters used to designate specific genes in this context. The T and t in this case could represent any gene, though the T clearly represents the dominant allele and the t represents the recessive allele.

By the way, in a simple, one-gene, dominant/recessive case an individual with one Dominant and one Recessive gene (Tt genotype) would have the trait in question, because the dominant allele overrides the recessive one. Only a person with a tt genotype would lack the trait.

Answer 2

A capital letter usually stands for the dominant allele of a pair.

Answer 3

The capital T represents the dominant allele for a particular gene.