Question

Which among the following shows a symbiotic association in its roots ?

• A. Cycas
• B. Pinus
• C. Pisum sativum
• D. All of the above

Answer 1

The correct option is D All of the above

The roots of Pinus show fungal association. These roots are called mycorrhiza. Fungi help to absorb water and minerals like phosphorus for the plant and the plant, in turn, provides nourishment. This type of beneficial association is called mutualism or symbiosis.

The coralloid roots of Cycas show symbiotic association with blue green algae. The blue green algae help in nitrogen fixation. Cycas provides a habitat for the cyanobacteria to grow.

The bacterium Rhizobium shares a symbiotic relationship with leguminous plants such as Pisum sativum, where it helps in the fixation of atmospheric nitrogen into nitrates that can be absorbed by the roots of the legumes.