What are elastomers? Plot the stress $\to$ strain curve for them and explain.

(N/A) Materials that can be stretched to cause large values of strain are called elastomers. Examples include rubber and the elastic tissues of the aorta.
Rubber can be pulled to several times its original length and still returns to its original shape.
The figure shows the stress $\to$ strain curve for the elastic tissue of the aorta,which is the large vessel carrying blood from the heart.
Key observations from the curve:
$1$. The elastic region is very large.
$2$. The material does not obey Hooke's law over most of this region.
$3$. There is no well-defined plastic region for these materials.