state gov UPSSSC Agriculture Technical Assistant Mock Test 2024 General Knowledge Ecology and Environment
With reference to the nitrogen cycle, consider the following statements.
1. Only a few types of organisms like certain species of soil bacteria and blue-green algae are capable of utilising nitrogen directly in its gaseous form.
2. Generally, nitrogen is usable only after it is fixed.
3. Only 1 per cent of fixed nitrogen is biological.
Which of the statements given above is/are correct?
1
1 and 2 only
2
2 only
3
1 and 3 only
4
1, 2 and 3