34. 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).

 

Elasticity

Plasticity

The elasticity is stretchability of the plant cells or products, e.g, tubber/latex etc. 

The elastic substances can revert back to its original form in relaxed state. 

e.g. stretching of rubber.

Different pathways in response to environment or phases of life to form different kinds of structure is called plasticity.

The plastic substances and phenomenon of plasticity are not reversible, i.e., irreversible. eg., difference in shapes of leaves produced in air and those produced in water in buttercup. This is also known as heterophylly.