<span>Well, there are five layers in the Earth's Atmosphere:
(In order from the inside out)
1) Troposphere - This is where weather occurs.
2) Stratosphere - This is the layer where jets fly, this is where jet-streams are found
3) Mesosphere - Meso ("Middle") named because it is in the middle. This is where meteros burn up in the atmosphere.
4) Thermosphere - Thermo ("Heat") Names because it is the hottest layer in the atmosphere. This is where the aurora borealis, or northern lights occur.
5) Exosphere - Exo ("Outer") This is the outmost layer and it is where the atmosphere merges with outer space.</span>
Explanation: there would not be a way to distinguish between Tt and TT without mating or DNA analysis because T is dominant in Tt, therefore has the same physical characteristics as TT.