Can rolled out roti be reversed back to dough?

Can whole of work be converted into heat? Is the reverse true?

A rubber band stretches and reverts back to its original position. Bubble gum stretches, but it would not return to its original position. Is there any difference between the two processes? Discuss it with respect to plant growth(Hint: Elasticity(reversible) Plasticity (irreversible).

Which of the following chages can not be reversed ?

Zinc can be coatd on iron to produce galvanized iron but the reverse is not possible. It is because

Can we say that ironing of a cloth is a reversible change?