It turns out that many materials can be solid at a higher temperature if the pressure is also higher. so even though it is hotter in the inner core the pressure in the core is also higher and you can have a solid iron nickel instead of liquid
The major difference is that plants use vacuoles to store excess amounts of water, while animal cells do not. A plant standing up straight compared to a plant wilting over is a result of water capacity in the vacuoles
