When water boils, it is a physical change. Just like when it freezes. You can change it back to its original state. That is the difference between a physical and chemical change.
<em> I hope this helps!
</em><em>~kaikers</em>
The interactions can be harmful because they can poison the organisms and they can be helpful because they can help improve the organisms surroundings ex. food/ water supply.
Your chances for tossing a head instead of a tail would be 50:50.
Cells in this area of the plant develop THICKENED CELL WALLS.
Cell wall is a very important cell organelle in plant, it gives rigidity to the plants' cells thus supporting them, it also perform a host of other activities. Thickened cell wall are usually rich in lignin. Thickened cell wall in plants are also called secondary cell wall.