What Are Biofertilizers

Q. name two hydrocolloids obtained from algae

Q. Which among the following is free living nitrogen fixing bacteria?

1. $\text{Bacillus licheniformis}$
2. $\text{Bacillus vulgaris}$
3. $\text{Salmonella}$
4. $\text{Clostridium}$

Q. A biofertilizer is

1. A cyanobacterium like Anabaena living in cavities of Azolla leaves
2. Symbiotic bacteria like Azotobacter which fix atmospheric nitrogen
3. Farm yard manure consisting of mixture of cattle dung and crop
4. Green manure in which quick growing crops are cultivated

Q. Write down the steps of conversion of atmospheric nitrogen to ammonia by nitrogenase enzyme?

Q. Which of these is NOT an advantage of using a bio fertilizer?

1. Improves soil fertility
2. Maintains the natural habitat of the soil
3. Prevents eutrophication
4. Provides specific nutrients in high concentrations