Answer:
The statistics
Step-by-step explanation:
Mendel experiments were different because he used peas because they were cheap, they grow relative fast, they have different kind of plants, that mean that he can focus in one characteristic at a time, like the color, the shape, the texture, etc.
So since he can do numbers with his results, the statistics were easy to do, were easy to observe the patterns in real life so he can do in theory other traits even in humans.
Hope this info was useful.