class 7 science chapter 10 mcq

19 Disease causing micro organisms are 1. vectors 2. pathgen 3. microbes 4. all

18 The milkmaids who developed cowpox develop immunity to 1. typhoid 2. smallpox 3. t.b 4. all

17 Small pox vaccine is invented by 1. edward jenner 2. ronald ross 3. louis pasteur 4. albert sabin

16 Micro organisms present in root nodules of leguminous plants 1. rhizobium 2. bacillus 3. azatobactor 4. nostoc