1. The nitrogen exists as two nitrogen atoms joined by

2. Phytotron is meant for

3. The enzyme involved in biological nitrogen fixation are

4. NPK denotes

5. Toxicity of which element leads to the appearance of brown spots on leaves

6. The requirement of micro nutrient are always low if the concentration increases it leads to

7. Presence of phosphorus

8. In cabbages, ‘Whiptail’ is a characteristic deficiency disease. It is caused by the deficiency of

9. Analysis of xylem sap shows

10. Which one of the following organism help in absorption of phosphorus from soil by plants

11. Exanthema is due to deficiency of

12. Minerals present in the soil are absorbed by

13. Insectivorous plants grow where

14. Conversion of ammonia into nitrates through Nitrosomonas is called

15. Which one of the following is not a micronutrient?

16. Biological nitrogen fixation was discovered by

17. Which element is required for opening and closing of stomata?

18. Phosphorous is a constituent of

• A. Cell membrane
• B. Nucleic acids
• C. cellwall
• D. chlorophyll
  

19. Which of the following is not a macronutrient

20. Oxygen scavangers present in root nodules of legumes is