Final answer:
To confirm the 1:2:1 ratio in the F2 generation, a test cross is performed by crossing the F2 generation with a homozygous recessive organism for the same trait.
Step-by-step explanation:
To confirm that the F2 generation has a 1:2:1 ratio of Tt, Tt, and tt trait combinations, you would perform a test cross. In a test cross, the F2 generation is crossed with an organism that is homozygous recessive for the same trait. If the F2 generation has the expected 1:2:1 genotypic ratio, then it confirms the predicted inheritance pattern. This validates Mendel's postulate that pairs of unit factors segregate equally.