Question

hardest substance of plant and animal respectively

Answer 1

in animal enamel is the hardest and sporopollelin is the hardest for plant

Answer 2

in plants sporopollenin. The one of the most resistant material in the plant kingdom. It is the chemical which forms the exine layer of the pollen grain. This thing is so much resistant that it can withstand high amount of alkali and acid exposures, and even till it will not get degraded. This is the reason that why the pollen grains can be stored for so long time.

in animal the layer around their teeth called enamel is the hardest part