Question

In the seed test, the damaged seeds float and the healthy seeds sink.​

Answer 1

The seeds that float on the surface of water are the damaged seeds and the ones which sink at the bottom of the tumbler are the healthy seeds.
The reason behind the healthy seeds to sink is because they are heavy, containing the essential nutrients.
The damaged seeds float on the water surface as they are hollow from the inside and lack essential nutrients. Hence they are lighter in weight and float.