Question

The cyanobacterium, Anabaena azollae, lives in association with ______.

Options

• roots of leguminous plants

• leaves of a floating fern

• roots of pine trees

• bacteria and fungi

Answer 1

The cyanobacterium, Anabaena azollae, lives in association with leaves of a floating fern.

Explanation:

Anabaena azollae lives in the leaf cavities of the floating fern Azolla and fixes nitrogen for it. Legume roots host Rhizobium, pine roots host fungal mycorrhizae, and bacteria and fungi are not its partners.