Name some organisms which fix atmospheric nitrogen directly.

Name the organisms which do not derive energy directly/indirectly from sun.

I. Unicellular. Colonial, filamentous, marine or terrestrial forms II. The colonial , filamentous, marine or terrestrial forms III. Some can fix atmospheric nitrogen in specialised cells called heterocysts IV. They often form blooms in water bodies. these above characters are seen in

Name some insects which live on plant.

Name the water fern, capable of fixing atmospheric nitrogen and used as biofertilizer.

Name two free living microorganisms which can fix nitrogen. Also write the name of the water ferm and a gymnosperm with whom some cyanobacteria have symbiotic association.

Name the organism which possesses one mitochondria.

Bacteria which directly convert atmospheric nitrogen into nitrogen compounds are called

A water fern capable of fixing atmospheric nitrogen and used as biofertilizer.

Name some living organism which does not have bone or skeleton?

Read the following statement regarding the mineral (i) Both Rhiqobium and Frankia are free living in soil, but as symbionts, can fix atmospheric nitrogen. (ii) Ammonia synthesis by nitrogenase requires 16 ATP for each ammonia produced. (iii) While most of plants can assimilate nitrate as well as ammonium ions, the latter is quite toxic to plnats and hence cannot accumulate in them. (iv) Along with the transpiration stream, the nodules of some plants export the fixed nitrogen as urides. Which of these are correct