How much nitrogen is fixed by blue-green algae in a paddy field in a year?

Write examples of blue -green algae.

Why are blue-green algae not popular as biofertilizers?

The common nitrogen fixer in paddy fields is

How much percent of nitrogen is present in atmosphere ?

How much amount of solar energy is trapped by green plants?

Name two nitrogen fixing algae.

How do the blue-green algae help in improvement of agriculture?

Describe the role of blue green algae in the fertility of soil.

Figure shows a metal rod PQ resting on the smooth rails AB and positioned between the poles of a permanent magnet. The rails, the rod, and the magnetic field are in three mutual perpendicular directions. A galvanometer G connects the rails through a switch K. Length of the rod =15 cm, B = 0.50 T, resistance of the closed loop containing the rod = 9.0 mOmega Assume the field to be uniform. How much power is required (by an external agent) to keep the rod moving at the same speed (= 12 cm s^-1 ) when K is closed? How much power is required when K is open? :

Cell wall of bacteria and blue green algae is composed of