The correct answer is radial symmetry.
This means that there's a central axis around which they are formed, which is similar to how starfish or tulips grow. Similarly put, it's like cutting a pie or a pizza through the axis and getting the same pieces.
1. Both are caused my osmosis
2. Both involve in the destruction of the cell (plasmolysis occurs in place cell walls and heamolysis occurs in red blood cells of animals