Assertion: A biosphere reserve is a specified area.
Reason: No restriction on human activities has been imposed in biosphere reserve.

Assertion (A) is true but Reason (R) is not correct.

Biosphere reserves are multipurpose protected areas, which are meant for preserving genetic diversity in representative ecosystems of various natural biomes and unique biological communities by protecting wild populations, traditional lifestyle of tribals, and domesticated plant/animal genetic resources. Multiple uses of the land are permitted by dividing it into zones, each for a particular activity.

These zones are- (i) Core (no human activity is there),(ii) buffer (limited human activity is permitted), (iii) manipulation zone (several human activities can occur in this zone).