If a plant has a genotype of Tt, what can be said about its phenotype?

In the context of plant genetics, the notation Tt typically indicates a heterozygous genotype, where T represents the dominant allele for tallness, and t represents the recessive allele for dwarfness. The presence of the dominant T allele means that the plant will express the tall phenotype, regardless of the presence of the recessive t allele.

In classical Mendelian inheritance, dominant traits are phenotypically expressed in the presence of at least one dominant allele. Since the plant with the Tt genotype has one dominant allele (T), it will be tall. This is why the correct answer is that the plant's phenotype is tall. The phenotype reflects the outward appearance or observable characteristics determined by the genotype you have, which in this case leads to the conclusion that the plant will be tall.