Coralloid roots of N2- fixing cyanobacteria have symbiotic association with
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) - Cycas
The coralloid roots of Cycas are symbiotically associated with nitrogen fixing blue-green algae, Anabaena cycadae and Nostoc punctiforme.
In the middle cortex of coralloid roots, there occurs a broad blue green zone, which is known as algal zone.
Coralloid roots are irregular, negatively geotropic, dichotomously branched coral likes roots which do not possess root hair and root caps.