Question

A filamentous nitrogen fixing bacterium is present in root nodules of flowering plants is

• A. Cicer arietinum
• B. Casuarina equisetifolia
• C. Cycas revoluta
• D. Crotalaria juncea

Answer 1

The correct option is B Casuarina equisetifolia

Nitrogen fixation is a process by which atmospheric nitrogen is converted into ammonium compounds and made available for plants. They are of two types, free living and symbiotic. Symbiotic nitrogen fixing bacteria are present in the root nodules of legumenous plants. Casuarina equisetifolia is a deciduous tree. It belongs to genus Casuarina. All the Casuarinas are nitrogen fixing. A filamentous nitrogen fixing bacteria, Frankia is present in the root nodules of flowering plant Casuarina equisetifolia.

Thus, the correct answer is 'Casuarina equisetifolia.'