what is the difference between biosphere reserves sanctuaries national parks and zoos

Biosphere Reserves are large areas for conservation of biodiversity, which include both wildlife and plants.  

Wildlife Sanctuary is an area which is free from disturbances from human activities, and is devoted for the conservation and protection of only wildlife.  

National Parks are those reserved areas where no human activity is allowed at all and the purpose of a national park is to preserve the plants, animals, landscape, and the historic objects of that area.  

A zoo or zoological park is a facility in which animals are confined within enclosures, displayed to the public, and in which they may also be bred.